So it is back. Yes. What do you propose to do about it?
You have been given many suggestions here but by the look of your browser not much has changed.
This means you have to do something more drastic. How about starting with a fresh, new, never-used-before drive?
Followed by:
Fresh install with a local account instead of a Microsoft account. Rufus is very helpful this way.
When you install Firefox don't register it with your email. Run blind. Trust me, you'll still be notified about critical updates and such.
NEVER synchronize your browsers. OF course, if you have a half decent old style desktop you can still keep your old OS and just boot to a newly installed one via DUAL or MULTIPLE boot. Personally, I wouldn't have it any other way. This way you get to have a real, decent, clutter free operating system and you have an OS to go get dirty with. Extensions can be dirty things, my friend. They often don't play fair. But if it floats your boat, have fun! Take charge! Be an Alpha! Go POLY!

Go multi-boot.