"Are you able to see your pc in your Microsoft account? What about the devices list during the activation troubleshooter?"
- Yes I can see both my devices one HP Victus laptop with Win 11 Home and my DIY DESKTOP for what I purchased RETAIL license of Win 11pro after the OM license was crushed after motherboard BIOS update.
Same as in your case the troubleshooter for some reason doesn’t see the DESKTOP and sees only the Laptop that’s messed up on MS licensing system or whatever is responsible for that.
Another similarity like in your case I also removed the DESKTOP from my account before installing fresh WIN 11 that was a standard procedure and I never had any issue in fact it was a procedure you should follow not to accumulate to many devices under your account.
I had old Win 8 & 10 retail license at least 4 of them that I purchased but I actually throw all them away ,CD’s, covers and everything after some major cleaning never came to my mind I will have any use for them ever again.
I was able to fish out an MS customer support number in my region just to be greeted with "This number is not in use " and the number came from legitimate MS Support page.
I assume they completely dropped the calls option and relay only on open tickets and then they call you or not like in our cases.
Very frustrating and painful and now I feel at a loss due to a license I paid and can’t use .