Based on your screenshots, you have no 3rd party modifications installed. The only plugin you have is disabled, so switching to PHP 8.0 shouldn't cause any issues.
The only thing I can think of is that the PHP 8.0 version is not compiled with all the required modules. Switch again to PHP 8.0 and use this script to verify the PHP version meets all requirements:
If the script returns any errors, ask your hosting to fix them.
If the script passes all checks, and you're unsure how to proceed, it would probably be best to hire a 3rd party Provider to look into it. While you're at it, you can also look into updating to the latest version since you're ~15 versions behind.