Firefox 89 auto-installed yesterday. Never did a restart (of my machine) because I was not prompted to.

Launched Firefox this morning and the browser was positioned at the very top of my desktop. I was kind of like hmm that's weird and not where I left it. Put the browser window back to my preferred position.

Opened Firefox->About Firefox to see if maybe an update came in overnight and that window was stuck to the top of my desktop as well. In the middle of my morning coffee, so figured I'd deal with it later.

Went to Twitch and was unable to control the volume. My mouse cursor kind of disappeared when I tried to use the volume control.

Finally did a restart of my machine and things went back to working but not sure if I'll stay with Firefox. Design doesn't mean much if the browser is not stable. Never had a problem previously to Firefox 89.