I'm on Android, using Firefox 79.0.5 (Build #2015758619) - which is like freshest bits for GP - it's where they moved the address bar to the bottom.
So, go to a long URL, like paging through a forum. Then edit the URL. Place cursor at end and hit bksp. As you continue to delete chars the purple-phantom highlight where it tries to autocomplete goes crazy and flickers the heck out of the UI. It's definitely a regression.
I don't know the best way to capture screen on this device tho, and I don't have time to spin up any emulators and go through those steps
> it's where they moved the address bar to the bottom
Yup, that's Fenix. By the way, you can switch it back to the top, but the (+) button (new tab) still remains at the bottom, which irks me.
I actually just tried and I'm not seeing your issue - but I have different issues (mainly that when I open the browser, the topmost tab can never seem to figure out whether it has a page loaded or it's on the new tab page).
By the way, I'm just a fellow user, so don't spend too much effort describing your bug to me, haha. It might be worth reporting it to their bug tracker, though: https://github.com/mozilla-mobile/fenix/issues
If your device happens to be a Samsung phone, it should come with a screen recorder (at least on the newest major version of Android)
