websites animation not working -

If website animations don't work even in Safe Mode reinstalling macOS may be justified: How to reinstall macOS - Apple Support.

Before doing that exhaust all the other suggestions in If Safari doesn't open a page or work as expected on your Mac - Apple Support.

This seems to suggest there is a System Wide Issue

Does anything in the below look familiar and used on this Specific Computer ?

1 - Disk Cleaner 

This will include CleanMyMac , aka “ BrickMyMac “

MacKeeper,

Dr Cleaner Pro Plus

Open Cleaner one Pro

Macmechanic

Clean my Mac x.

2  - Third Party Security Software 

This will include BitDefender , 

This will included Norton Antivirus 

 Sophos Av Software

Intego AntiVirus

 McAfee, 

Avast AntiVirus

Ad Guard,

 Webroot ,

 ESET ,

 Avira ,

AVG AntiVirus  

 avira antivirus 

Trustee  

AntiVirus for Mac

F-Secure

Securemac

Cylance

Kaspersky Internet Security

Total Virus Software 

VirusOne

Remove Virus One 

Read some of the posting and arrive at your own conclusions.

The The Built in Security  is all that is required.

I understand many websites with animations are not working. Please determine if the same problems occur in "Safe Mode": Use safe mode on your Mac - Apple Support

Check Safari settings and make sure Auto play features are turned on then refresh page.