Weird installation behavior on PC

Hello. So I buy the discounted car pass and install it. Then notice that the load times have drastically worsened. Then I find an official reply that this is a known issue, please install only the base game and the 2 DLCs. So I uninstall the game. When I then click “Install”, from the remaining GBs on my disk I think that the games files are still there. The store “downloads” my game at ~600Mb/s when in reality my max speed is 100 but in the past it never reached that. So the game finishes “downloading” (more like rechecking the files already there?) quite quickly. But the load times are not improved. When I uninstall the game and go to the WindowsApps folder (again, after googling for 20 mins how to do that), I see no folder with “sunrise” in it (that’s how FH4 is called lol). It only appears when the store is starting to “download” the game. Anyways, for those of you who read it all, any suggestions apart reinstaling Windows :D?