Make sure you are not blocking content.

Diagnose Firefox issues using Troubleshoot(Safe) Mode {web link}

A small dialog should appear. Click Start In Troubleshoot(Safe) Mode (not Refresh). Is the problem still there?

https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop

Many site issues can be caused by corrupt cookies or cache.

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

• Delete cookies to remove the information websites have stored on your computer {web link}

• How to clear the Firefox cache {web link}acking-protection-firefox-desktop

This answer makes no sense to me; please explain. I stated that I had already tried Troubleshoot Mode and then I did a complete uninstall, deleted the profile, and did a new install. Everything on the laptop is now a clean install with default settings. I did not restore anything from the old profile.

On the laptop, I re-tried Troubleshoot Mode with the fresh install and the problem still persists.

On the laptop, I toggled tracking off and on and the problem persists. On the desktop, the picture scrolls with or without tracking protection.

Next steps?

Remove History For One Site {web link}

Open the History Manager <Control> (Mac=<Command>) <Shift> H. In the search bar, enter the name of the site. Right-click on one of the listings and select Forget About This Site. This should remove all information, including any site settings

Do you possibly have set ui.prefersReducedMotion = 1 on the about:config page to minimize the amount of non-essential motion ?

• in Firefox 78+ this includes the location bar breakout
• in Firefox 80+ this replaces the tab loading indicator with an hourglass

See also:

• https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-reduced-motion

You can open the about:config page via the location/address bar. You can click the button to "Accept the Risk and Continue".

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

Do you possibly have set ui.prefersReducedMotion = 1 on the about:config page to minimize the amount of non-essential motion ?

• in Firefox 78+ this includes the location bar breakout
• in Firefox 80+ this replaces the tab loading indicator with an hourglass

See also:

• https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-reduced-motion

The ui.prefersReducedMotion isn't set.

Going to the CSS page, the box pulses on both machines.

Further troubleshooting shows the problem persists on the laptop with Chrome and MS Edge. It works on the desktop and Android. So the problem is definitely something with the site. Thanks for your help.

For completeness and in case anyone was curious... The solution has been found. Windows 10 Home "animate controls and elements inside windows" was off.

That was very good work. Well Done. Please flag your last post as Solved Problem as this can help others with similar problems.

For more information: How To Enable Or Disable Animate Controls And Elements Inside Windows 10?

Note that this is mentioned in the article I linked above :

• https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-reduced-motion#user_preferences

For Firefox, the reduce request is honoured if: In Windows 10: Settings > Ease of Access > Display > Show animations in Windows. In Windows 7: Control Panel > Ease of Access > Make the computer easier to see > Turn off all unnecessary animations (when possible).

Note that this is mentioned in the article I linked above :

• https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-reduced-motion#user_preferences

For Firefox, the reduce request is honoured if: In Windows 10: Settings > Ease of Access > Display > Show animations in Windows. In Windows 7: Control Panel > Ease of Access > Make the computer easier to see > Turn off all unnecessary animations (when possible).

Note that this wasn't the setting that was causing the problem. "Show animations in Windows" was already turned on.

Sorry, I'm not using Windows, so I'm not familiar with the possible settings in Window 10.

Thanks for the clarification.