Forza Horizon 4 Ultimate Edition - Car DLCs not usable

Hi,

last year i preordered the Ultimate Edition of Forza Horizon 4. I had no problems until this June.
I was installing the latest Windows updates for my pc (OS: Windows 10 Pro, Build 18362.207). So far so good, everything seems working fine after installing those updates.

But after starting Forza Horizon 4 (or even Forza Horizon 3, which i also own the Ultimate Edition), i can´t use the Carpass DLC anymore. Fortune Island and Lego Champions are working fine, only the carpass doesnt work.
So i looked into the new control panel and saw, that the carpass was missing. So downloaded the carpass via the Microsoft Store again and now it shows up in the control panel app section.
However, the game still does not recognize the carpass. I can´t use my cars in my garage, because everytime the game says “You do not own this dlc. Buy it on the marketplace or remove it from your garage” (its translated, because my Forza is not english)

What i did until now:

  • Reinstalling the Carpass Addon from the Microsoft Store
  • Doing an WSRESET (as Administrator of course)
  • Resetting Forza Horizon via the new control panel

The behavior above is the same for my Forza Horizon 3 game: Blizzard Mountain and Hot Wheels working like a charm, but the carpass doesnt work.

Also the problem only occurs on my Windows 10 pc not on my Xbox. Its working great there but this is not an solution.