Bug 148624, which was opened 22 years ago, has finally been closed. The bug involved tooltips from another application appearing over Mozilla, causing annoyance for users. Many users reported the issue over the years, with screenshots and details provided. Surprisingly, the bug has 8 duplicates and 15 votes, indicating its significance. Some users suggested that the bug should be given a higher severity, while others found workarounds, such as disabling tooltips entirely. The bug has been fixed in version 119 of Firefox. It is worth noting that the bug only occurs when MOZ_ENV_XINPUT2 is set to 1.
https://bugzilla.mozilla.org/show_bug.cgi?id=148624