User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:73.0) Gecko/20100101 Firefox/73.0

Steps to reproduce:

The graphic ui glitch usually happens every couple of days randomly. I saw the blog post to help find the bug so I tried to do things to force it. I got it to happen three times in a row. One thing that was different when I tested this is the glitch only happens on the tab/url bar. On the other random occurrences the glitch causes black boxes on website page as well.

1. Open a session with a lot of website tabs (until the tab bar scrolls).
2. Use AHK to open/close tabs 200+ times in quick succession (300ms delay ctrl-t/ctrl-w)
3. Browse normally for 40-60mins then ui glitch appears suddenly when you hover over something that creates a popup textbox (tab/url/alt txt).

Actual results:

Tabs are blank with missing images and/or url bar cut off. I redact some stuff in screenshots, but looking at tab bar is obvious. Screenshot #2 shows it the most.

The priority flag is not set for this bug.
:jbonisteel, could you have a look please?

For more information, please visit auto_nag documentation.

We have a potential fix that is in beta (https://www.mozilla.org/en-CA/firefox/channel/desktop/) would you be willing to try out Beta and see if you can reproduce the issue?

I haven't seen the glitch in beta or stable (74.0) or nightly for the last 4 days.

Suspected fix has shipped with FF 75, we will reopen if this becomes an issue again

Fixed by bug 1617083

Bugbug thinks this bug is a regression, but please revert this change in case of error.