How are you opening bookmarks when Firefox is in full screen -- is that from sidebar? Also, do you mean the F11 type of full screen, or the content style (such as clicking a button on the video player)?

You could post the video on a video sharing site (such as YouTube, Vimeo, or Imgur) and provide a link to it in a reply. Links to non-Mozilla sites may divert your post to the spam moderation queue, so if that happens, it's normal.

Can you give more detail on how you are opening the bookmarks ? Is this about opening the bookmarks sidebar or are you opening a menu or are you displaying the Bookmarks Toolbar or something else ?

• https://support.mozilla.org/en-US/kb/use-firefox-sidebar-access-bookmarks-history-synced
• https://support.mozilla.org/en-US/kb/bookmarks-toolbar-display-favorite-websites

How are you opening bookmarks when Firefox is in full screen -- is that from sidebar? Also, do you mean the F11 type of full screen, or the content style (such as clicking a button on the video player)? You could post the video on a video sharing site (such as YouTube, Vimeo, or Imgur) and provide a link to it in a reply. Links to non-Mozilla sites may divert your post to the spam moderation queue, so if that happens, it's normal.

https://imgur.com/a/f3ghjgR

You can see that it kind of glitches out when I click the bookmarks and they load.

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 userChrome.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

One other thought: do you have multiple monitors with different display resolutions?

One other thought: do you have multiple monitors with different display resolutions?

I have 2 monitors (My main ones) That are 1920x1080, although I do have a drawing tablet that's 1366x768.

Thanks. Firefox is more likely to think the "proper" resolution is the one from the screen it first launched on, so that probably rules out the tablet.

Did Troubleshoot Mode work any better?

Thanks. Firefox is more likely to think the "proper" resolution is the one from the screen it first launched on, so that probably rules out the tablet. Did Troubleshoot Mode work any better?

I haven't tried that strategy yet, but I'll do that tomorrow. It's getting late in my country and I have things to do tomorrow. Until then, thanks for your help! :)