Randomly, out of seemling nowhere, my extensions are gone. I reinstalled brave, to no avail they are still gone, but a new extension found itself on my brave, called “Adblock”. I have never installed this adblock in my life. When I restart my pc, all my extensions come back but brave will quickly crash and reopen itself and when I go to extensions it will just be that lone ablock sitting there.
This definitely seems like the work of some malware or potentially one of your other extensions installing this one without your permission. Can you please try removing this extension in the browser and confirm whether or not it reappears?
I would also recommend running a virus scan on your PC to ensure you do not have any malware running on your system.