Steps to reproduce:
Open a few tabs with CMD-click, switch to one, close it and re-open it with CMD-Shift-T. Doing this for one or more tabs causes sidebar to glitch and act weird when trying to switch to re-opened tabs.
Opening tabs, closing them and reopening them acts as intended, updating the sidebar state in predictable ways back and forth. Clicking on re-opened tabs, rearranging them and switching to them with keyboard shortcuts works.
Orion, OS version; hardware type:
Orion: Version 0.99.116-beta (WebKit 614.1.20)
macOS Monterey 12.4, MacBook Pro (16-inch, 2021), Apple M1 Max