Direct quote from my ongoing live chat;

Alright. That's great to know. Actually, there are a lot of fellow gamers out there experiencing the issue after the latest COD update.

Nothing to worry, since you are not the only one experiencing the issue. I believe the issue is with the game itself after the latest update.

I believe the issue is specific to this game only right?

Since you have already exhausted all possible troubleshooting steps, I would recommend contacting Activision so that they will be able to provide you further insights about the issue as well as check your in-game account on their system.

Live chat ended with me being told Activision are aware of the issue, but ive to apply for a refund, for a game bought in 2019.... this is going to be fun