b3rrytech

YES!  I managed to solve it! It was a typo in the alternative web-UI file path.
 
The solution was, after the above to get out of the loop, to stop all docker containers and edit the path line in qBittorrent.conf found in the appdata folder.
This is the line to look for if anyone is wondering:
 
For a novis like me it's a great satisfaction to be able to solve something myself. 🥳
 

Just recapping what happened in the end.
 
The last week it got so bad I couldn't boot anything at all, no Live-USBs or anything.

So after months of trying to find the problem I finally couldn't narrow it down any more than to the MB or the CPU. Since I had so many errors that pointed to the CPU I decided to open a warranty ticket with Intel. They accepted after I presented my evidence of my problems and replaced my CPU with a new one.
 
Very nice experience dealing with the support, and I'm glad I bought the boxed and not the trayed version of the CPU since the trayed had shorter warranty. At least for 11th gen, I think the warranty aren't differentiated in the newer generations.
 
Now it runs good again. 👍

For me, the CPU ended up being faulty and Intel replaced it.

OK, seems like Unpackerr is the problem and not my setup. I didn't think it was Unpackerr at first because I have three more instances that is running :latest just fine. Perhaps that's because they have Sonarr connections and the non working ones haven't..
I downgraded to version 0.10.1 for those with "[PANIC] runtime error" and that worked.