Should this help, below debug logs of me creating said bookmark then trying the search:
[2023-12-30 23:01:18] TabViewModel: processAction action: configureContentBlocker(enabled: true)
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.1, animated: false)
[2023-12-30 23:01:18] NewTabViewController ID 12: updateMainViewVisibility url: https://www.youtube.com/?yt=, animated: true
[2023-12-30 23:01:18] UIView.showHideAnimated: <Orion.WebContextView: 0x13a0f6e00; frame = (0 0; 430 751); autoresize = W+H; gestureRecognizers = <NSArray: 0x2839c82d0>; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830005a0>>, show: true, checkCurrent: true
[2023-12-30 23:01:18] UIView.showHideAnimated: <Orion.NewStartView: 0x1370c19a0; frame = (0 -1; 430 752); alpha = 0; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x283005a40>>, show: false, checkCurrent: true
[2023-12-30 23:01:18] TabViewModel: WebPageDelegate: urlUpdated: https://www.youtube.com/?yt=, webPage: Orion.WebPageModel
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: urlDidChange
[2023-12-30 23:01:18] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://www.youtube.com/?yt=")
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://www.youtube.com/?yt=")
[2023-12-30 23:01:18] TabViewModel: WebPageDelegate: isLoading: true, webPage: Orion.WebPageModel
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: pageLoadingStatusChanged
[2023-12-30 23:01:18] NewTabViewController ID 12: updateBarsItems
[2023-12-30 23:01:18] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://www.youtube.com/?yt=")
[2023-12-30 23:01:18] TabViewModel: processAction action: updateLocationBar
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: updateLocationBar(viewModel: Orion.WebPageModel, tabsCount: 1)
[2023-12-30 23:01:18] TabViewModel: processAction action: updateToolsbar
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: updateToolsbar(tabHasURL: true, backNavigation: Orion.NewTabViewModel.BackNavigation.regular)
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: restoreToolbars
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: removeReaderModeHighlightFromURLBar
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: faviconUpdated(image: Optional(<UIImage:0x2807659e0 anonymous {16, 16} renderingMode=automatic(original)>))
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.15, animated: false)
[2023-12-30 23:01:18] NewTabViewController ID 12: updateMainViewVisibility url: https://m.youtube.com/?yt, animated: true
[2023-12-30 23:01:18] UIView.showHideAnimated: <Orion.WebContextView: 0x13a0f6e00; frame = (0 0; 430 751); autoresize = W+H; gestureRecognizers = <NSArray: 0x2839c82d0>; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830005a0>>, show: true, checkCurrent: true
[2023-12-30 23:01:18] UIView.showHideAnimated: <Orion.NewStartView: 0x1370c19a0; frame = (0 -1; 430 752); alpha = 0; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x283005a40>>, show: false, checkCurrent: true
[2023-12-30 23:01:18] TabViewModel: WebPageDelegate: urlUpdated: https://m.youtube.com/?yt, webPage: Orion.WebPageModel
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: urlDidChange
[2023-12-30 23:01:18] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/?yt")
[2023-12-30 23:01:18] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/?yt")
[2023-12-30 23:01:18] TabViewModel: processAction action: configureContentBlocker(enabled: true)
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.3, animated: true)
[2023-12-30 23:01:19] JSAPI: Error: Attempting to use runtime from web extension background context.
[2023-12-30 23:01:19] JSAPI: Error: browser.runtime.Port.portMessage invalid port
[2023-12-30 23:01:19] JSAPI: Error: browser.tabs.sendMessage is using unimplemented options. (["frameId"])
[2023-12-30 23:01:19] JSAPI: Error: browser.runtime.Port.portMessage invalid port
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.82097733, animated: true)
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.8251662, animated: true)
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 1.0, animated: true)
[2023-12-30 23:01:19] TabViewModel: WebPageDelegate: isLoading: false, webPage: Orion.WebPageModel
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: pageLoadingStatusChanged
[2023-12-30 23:01:19] NewTabViewController ID 12: updateBarsItems
[2023-12-30 23:01:19] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/?yt")
[2023-12-30 23:01:19] TabViewModel: processAction action: updateLocationBar
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: updateLocationBar(viewModel: Orion.WebPageModel, tabsCount: 1)
[2023-12-30 23:01:19] TabViewModel: processAction action: updateToolsbar
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: updateToolsbar(tabHasURL: true, backNavigation: Orion.NewTabViewModel.BackNavigation.regular)
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: removeReaderModeHighlightFromURLBar
[2023-12-30 23:01:19] NewTabViewController ID 12: processViewModel w/ state: faviconUpdated(image: Optional(<UIImage:0x2807019e0 anonymous {16, 16} renderingMode=automatic(original)>))
[2023-12-30 23:01:19] BrowserContainerVC: storeSessionURLs
[2023-12-30 23:01:20] NewTabViewController ID 12: processViewModel w/ state: faviconUpdated(image: Optional(<UIImage:0x280765290 anonymous {16, 16} renderingMode=automatic(original)>))
[2023-12-30 23:01:20] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.0, animated: false)
[2023-12-30 23:01:20] TabViewModel: processAction action: takeScreenshot(tabRootView: Optional(<Orion.NewTabRootView: 0x1370c17b0; frame = (0 0; 430 751); backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830db900>>))
[2023-12-30 23:01:22] NewTabViewController ID 12: updateMainViewVisibility url: https://m.youtube.com/?yt#searching, animated: true
[2023-12-30 23:01:22] UIView.showHideAnimated: <Orion.WebContextView: 0x13a0f6e00; frame = (0 0; 430 751); autoresize = W+H; gestureRecognizers = <NSArray: 0x2839c82d0>; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830005a0>>, show: true, checkCurrent: true
[2023-12-30 23:01:22] UIView.showHideAnimated: <Orion.NewStartView: 0x1370c19a0; frame = (0 -1; 430 752); alpha = 0; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x283005a40>>, show: false, checkCurrent: true
[2023-12-30 23:01:22] TabViewModel: WebPageDelegate: urlUpdated: https://m.youtube.com/?yt#searching, webPage: Orion.WebPageModel
[2023-12-30 23:01:22] NewTabViewController ID 12: processViewModel w/ state: urlDidChange
[2023-12-30 23:01:22] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:22] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/?yt#searching")
[2023-12-30 23:01:22] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/?yt#searching")
[2023-12-30 23:01:22] NewTabViewController ID 12: processViewModel w/ state: pageLoadingStatusChanged
[2023-12-30 23:01:22] NewTabViewController ID 12: updateBarsItems
[2023-12-30 23:01:22] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:22] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/?yt#searching")
[2023-12-30 23:01:22] TabViewModel: processAction action: updateLocationBar
[2023-12-30 23:01:22] NewTabViewController ID 12: processViewModel w/ state: updateLocationBar(viewModel: Orion.WebPageModel, tabsCount: 1)
[2023-12-30 23:01:22] TabViewModel: processAction action: updateToolsbar
[2023-12-30 23:01:22] NewTabViewController ID 12: processViewModel w/ state: updateToolsbar(tabHasURL: true, backNavigation: Orion.NewTabViewModel.BackNavigation.regular)
[2023-12-30 23:01:22] TabViewModel: processAction action: configureContentBlocker(enabled: true)
[2023-12-30 23:01:25] NewTabViewController ID 12: updateMainViewVisibility url: https://m.youtube.com/results?sp=mAEA&search_query=test, animated: true
[2023-12-30 23:01:25] UIView.showHideAnimated: <Orion.WebContextView: 0x13a0f6e00; frame = (0 0; 430 751); autoresize = W+H; gestureRecognizers = <NSArray: 0x2839c82d0>; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830005a0>>, show: true, checkCurrent: true
[2023-12-30 23:01:25] UIView.showHideAnimated: <Orion.NewStartView: 0x1370c19a0; frame = (0 -1; 430 752); alpha = 0; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x283005a40>>, show: false, checkCurrent: true
[2023-12-30 23:01:25] TabViewModel: WebPageDelegate: urlUpdated: https://m.youtube.com/results?sp=mAEA&search_query=test, webPage: Orion.WebPageModel
[2023-12-30 23:01:25] NewTabViewController ID 12: processViewModel w/ state: urlDidChange
[2023-12-30 23:01:25] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:25] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/results?sp=mAEA&search_query=test")
[2023-12-30 23:01:25] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/results?sp=mAEA&search_query=test")
[2023-12-30 23:01:25] NewTabViewController ID 12: processViewModel w/ state: pageLoadingStatusChanged
[2023-12-30 23:01:25] NewTabViewController ID 12: updateBarsItems
[2023-12-30 23:01:25] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:25] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://m.youtube.com/results?sp=mAEA&search_query=test")
[2023-12-30 23:01:25] TabViewModel: processAction action: updateLocationBar
[2023-12-30 23:01:25] NewTabViewController ID 12: processViewModel w/ state: updateLocationBar(viewModel: Orion.WebPageModel, tabsCount: 1)
[2023-12-30 23:01:25] TabViewModel: processAction action: updateToolsbar
[2023-12-30 23:01:25] NewTabViewController ID 12: processViewModel w/ state: updateToolsbar(tabHasURL: true, backNavigation: Orion.NewTabViewModel.BackNavigation.regular)
[2023-12-30 23:01:45] UIView.showHideAnimated: <UIButton: 0x127088ad0; frame = (0 0; 0 0); alpha = 0; opaque = NO; tintColor = <UIDynamicCatalogSystemColor: 0x28204c100; name = labelColor>; gestureRecognizers = <NSArray: 0x282693a20>; layer = <CALayer: 0x283d53720>>, show: true, checkCurrent: false
[2023-12-30 23:01:48] NewTabViewController ID 12: handleLocationChange searchString: yt test
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.1, animated: false)
[2023-12-30 23:01:48] NewTabViewController ID 12: updateMainViewVisibility url: https://www.qwant.com/?q=yt+test, animated: true
[2023-12-30 23:01:48] UIView.showHideAnimated: <Orion.WebContextView: 0x13a0f6e00; frame = (0 0; 430 751); autoresize = W+H; gestureRecognizers = <NSArray: 0x2839c82d0>; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830005a0>>, show: true, checkCurrent: true
[2023-12-30 23:01:48] UIView.showHideAnimated: <Orion.NewStartView: 0x1370c19a0; frame = (0 -1; 430 752); alpha = 0; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x283005a40>>, show: false, checkCurrent: true
[2023-12-30 23:01:48] TabViewModel: WebPageDelegate: urlUpdated: https://www.qwant.com/?q=yt+test, webPage: Orion.WebPageModel
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: urlDidChange
[2023-12-30 23:01:48] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "yt test")
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://www.qwant.com/?q=yt+test")
[2023-12-30 23:01:48] TabViewModel: WebPageDelegate: isLoading: true, webPage: Orion.WebPageModel
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: pageLoadingStatusChanged
[2023-12-30 23:01:48] NewTabViewController ID 12: updateBarsItems
[2023-12-30 23:01:48] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "yt test")
[2023-12-30 23:01:48] TabViewModel: processAction action: updateLocationBar
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateLocationBar(viewModel: Orion.WebPageModel, tabsCount: 1)
[2023-12-30 23:01:48] TabViewModel: processAction action: updateToolsbar
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateToolsbar(tabHasURL: true, backNavigation: Orion.NewTabViewModel.BackNavigation.regular)
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: restoreToolbars
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: removeReaderModeHighlightFromURLBar
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: faviconUpdated(image: Optional(<UIImage:0x280780ea0 anonymous {196, 196} renderingMode=automatic(original)>))
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.15, animated: false)
[2023-12-30 23:01:48] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "yt test")
[2023-12-30 23:01:48] TabViewModel: processAction action: configureContentBlocker(enabled: true)
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.3, animated: true)
[2023-12-30 23:01:48] JSAPI: Error: Attempting to use runtime from web extension background context.
[2023-12-30 23:01:48] JSAPI: Error: browser.runtime.Port.portMessage invalid port
[2023-12-30 23:01:48] JSAPI: Error: browser.tabs.sendMessage is using unimplemented options. (["frameId"])
[2023-12-30 23:01:48] JSAPI: Error: browser.runtime.Port.portMessage invalid port
[2023-12-30 23:01:48] NewTabViewController ID 12: updateMainViewVisibility url: https://www.qwant.com/?q=yt+test&t=web, animated: true
[2023-12-30 23:01:48] UIView.showHideAnimated: <Orion.WebContextView: 0x13a0f6e00; frame = (0 0; 430 751); autoresize = W+H; gestureRecognizers = <NSArray: 0x2839c82d0>; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830005a0>>, show: true, checkCurrent: true
[2023-12-30 23:01:48] UIView.showHideAnimated: <Orion.NewStartView: 0x1370c19a0; frame = (0 -1; 430 752); alpha = 0; backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x283005a40>>, show: false, checkCurrent: true
[2023-12-30 23:01:48] TabViewModel: WebPageDelegate: urlUpdated: https://www.qwant.com/?q=yt+test&t=web, webPage: Orion.WebPageModel
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: urlDidChange
[2023-12-30 23:01:48] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "yt test")
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "https://www.qwant.com/?q=yt+test&t=web")
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: faviconUpdated(image: Optional(<UIImage:0x280783570 anonymous {196, 196} renderingMode=automatic(original)>))
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.9, animated: true)
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 1.0, animated: true)
[2023-12-30 23:01:48] TabViewModel: WebPageDelegate: isLoading: false, webPage: Orion.WebPageModel
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: pageLoadingStatusChanged
[2023-12-30 23:01:48] NewTabViewController ID 12: updateBarsItems
[2023-12-30 23:01:48] TabViewModel: processAction action: updateWebsiteAddress
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateWebsiteAddress(text: "yt test")
[2023-12-30 23:01:48] TabViewModel: processAction action: updateLocationBar
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateLocationBar(viewModel: Orion.WebPageModel, tabsCount: 1)
[2023-12-30 23:01:48] TabViewModel: processAction action: updateToolsbar
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: updateToolsbar(tabHasURL: true, backNavigation: Orion.NewTabViewModel.BackNavigation.regular)
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: removeReaderModeHighlightFromURLBar
[2023-12-30 23:01:48] NewTabViewController ID 12: processViewModel w/ state: faviconUpdated(image: Optional(<UIImage:0x280781c20 anonymous {196, 196} renderingMode=automatic(original)>))
[2023-12-30 23:01:48] BrowserContainerVC: storeSessionURLs
[2023-12-30 23:01:49] NewTabViewController ID 12: processViewModel w/ state: pageLoadingProgressChanged(progress: 0.0, animated: false)
[2023-12-30 23:01:49] BrowserContainerVC: openOptionsPopover, hasURL: true
[2023-12-30 23:01:49] NewTabViewController ID 12: updatePopoverSourceView
[2023-12-30 23:01:49] TabViewModel: processAction action: takeScreenshot(tabRootView: Optional(<Orion.NewTabRootView: 0x1370c17b0; frame = (0 0; 430 751); backgroundColor = <UIDynamicSystemColor: 0x282067040; name = systemGray6Color>; layer = <CALayer: 0x2830db900>>))