It is quite normal to see a focus ring if you hover a clickable element, but this should be removed if you move the mouse out of the browsing area.

Firefox has several browser.display.focus pref on the about:config page that you can look at to see if they are all default.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

It might be bug 1807687, fixed in 110.

It might be bug 1807687, fixed in 110.

Yeah, thank you I found out this myself few days ago via reddit, had no time to post here. This is definitely a bug which is scheduled to be fixed in 110 (should be released on 14.02.2022 according to Firefox release calendar)

I still have this issue in v110.0. With the default settings every link, input, textarea and select has this blue outline if I click on them with the mouse. If I set 'browser.display.focus_ring_on_anything' to true then the outline is the old dotted black (not gray) line now and it's still on everywhere. If I set 'browser.display.focus_ring_style' from 1 to 0 while the previous setting is false (new outline) nothing happens, if it's true (old dotted) then it's a solid line now. If I set 'browser.display.focus_ring_width' to 0 it finally disappears as it shouldn't show up all the time in my opinion. But I don't want it to completely disappear. I don't know how was it previously, but I see them too many times now. Accessibility is not enabled.

I suggest you open a new thread as this one has been marked as answered.