Steps to reproduce:
Open one or more tabs on the iOS app, and navigate through a few pages in the tab(s) so that the back button is available, allowing navigation back through the browsing history of the tab. Swipe up to return to the Home Screen, and don't use your phone for a bit (or use some other apps for a while). Then re-open Orion, and note that you cannot use the back button on any tabs any longer.
Each tab retains its history so that when you return later, you can still navigate back using the back button or swipe gesture. Tested this in Safari, and it works as expected.
Orion, OS version; hardware type:
Orion: 184.108.40.206 (WebKit 86220.127.116.11.7)
iOS: 15.5 (19F77) on iPhone 13 Pro Max
Not sure images or video would help (or even be possible) but can try to gather if needed.