I was able to reproduce the issue on 91.0 build on Win10x64 and Ubuntu 20.4 and confirmed that the issue is fixed but the badge does not display the 4th digit at all after the fix. So reopen the issue in order to fix the badge display (see attached screenshot).
Bug 1714135 Comment 8 Edit History
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I was able to reproduce the issue on 91.0 build on Win10x64 and Ubuntu 20.4 and confirmed that the issue is fixed (does not flick - on 95.0b1) but the badge does not display the 4th digit at all after the fix. So reopen the issue in order to fix the badge display (see attached screenshot).