Hi, it shows here that you are running version 53 of FireFox could you please update to latest version https://support.mozilla.org/en-US/kb/update-firefox-latest-version Hopefully this will "help" Please follow up with this after updating if not fixed.

Note that help shows as a '?' in the "3-bar" Firefox menu button drop-down list.

You can tap the Alt key or press F10 to show the Menu Bar with the Help menu.

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

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

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