This still works for me in Firefox 110.

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

Thank you. I might have solved it, or found a workaround, but if it's not supposed to be that way then of course there is something causing this that was never there before. I will get back to you to see how it goes.

Now that I've got you and we're on the subject, Firefox seriously, MOST seriously, needs to bring back the "Bookmark All Tabs" command and have a "Save All Tabs" command of its own. There are no third-party apps and Add-Ons that do this very well anymore or at all, the older ones that used to do this no longer work well or at all. Firefox needs them in the browser to stay. It's never been the same without the "Bookmark All Tabs" command and trying to "Save All Tabs" the same way you would save a single page with "Save Page As" is frustratingly impossible to do. Any older Add-On or program that did this no longer works well or at all and hasn't for almost a decade or longer. It needs to be a standard function of any advanced browser. Firefox needs these functions as the normal standard. So, bring this up with your design team as an imperative because my having to migrate to these other lesser capable browsers the way others have doesn't appeal to me when Firefox should be a decade beyond their design and development, especially for functions that shouldn't be difficult hurdles for any modern browser to have.