FreeBSD 12.2-STABLE/amd64, ports head @ 548931. The display of tooltips seems broken for Firefox 81.0rc2. They pop up and immediately disappear again, too quick to read. This affects tooltips on page content and for the built-in PDF reader, but not those for the Fx user interface.
Web content or browser chrome? Either way I can't reproduce inside 12.1 amd64 jail both on X11 (via Xwayland) and Wayland (via MOZ_ENABLE_WAYLAND=1). RC2 is now the release. Try reporting upstream instead after reproducing in a fresh profile.
As I wrote above, it only affects web content and not browser chrome. It also happens with a fresh profile. I also see it on OpenBSD on different hardware. So far I have been unable to find anybody else who can reproduce this. I have no idea how to narrow this down.
Christian, have you tested with Firefox in safe mode? -- Re: https://lists.freebsd.org/pipermail/freebsd-questions/2020-September/291726.html Not reproducible here with Firefox 81.0_2,2 in safe mode on FreeBSD-CURRENT r366136. Tested: <https://xkcd.com/198/>
(In reply to Graham Perrin from comment #3) Same problem in safe mode. firefox-81.0.1,2 at this point.
amd64 12.2-RELEASE. I see the problem with this HTML: <html> <a title="some title text">some text</a> </html> This is with a fresh install and profile. Thoughts on tracking this down? I use some applications that rely on my being able to see this title text and its driving me nuts!
The problem has been introduced by this upstream commit: "Avoid unnecessary coordinate conversions when showing tooltips" https://hg.mozilla.org/mozilla-central/rev/9b17a5aeded6590078ba7bad625d126a9cf3edd0 Reverting this fixes 82.0.2 for me. I have not looked deeper yet.
I have opened a bug at the Mozilla upstream: https://bugzilla.mozilla.org/show_bug.cgi?id=1676020
Fixed upstream in 2022.