It seems like this happens after having Orion open over night.
Interesting observation. Do you perhaps have sync enabled? Do you also use Orion on iOS, and after maybe leaving your desktop / laptop, you may have picked up browsing on your phone?
I still haven't been able to reproduce this one consistently, but the overnight thing suggests that there's maybe some sync operation going on in the background causing the data for number of tabs to changes, which the tabs toolbar doesn't get an update for - thus making them go out of whack and then blocking further tab operations.
I'll look into this, but if you find any concrete steps to reproduce this, that'd be awesome.
On a slightly unrelated note, in your video at 0:06 seconds, you have focus mode on and toolbar hidden, but you then used some shortcut to get focus on the location bar and started typing google. What shortcut did you use to get focus on the location bar without moving your mouse? (I'm assuming it was just Cmd + T?)
It also looks like your browser is already in the broken state as soon as the toolbar appears in second 0:07. It shows 3 tabs, but you have no tabs showing in the compact toolbar, just the 2 pinned ones.
