So… no idea what happened but it works again.

Just in case anyone stumbles upon this thread at some point here are my current settings:

• The compatibility layer is proton-ge-custom (from AUR)
• Steam Input Translation in the Forza Horizon 4 Controller Settings is enabled using the “Official Layout for Forza Horizon 4 - Gamepad”
• Regular mode (not big picture mode)
• Steam Overlay is enabled

I still have the issue that on some screens it shows the keyboard buttons and not the controller buttons but since the controller works anyway I don’t really care (it’s just the optics).

Thanks everyone for your suggestions! :)

I only have this one game that I need a controller for

So install back both disks, make a bootable gparted stick and do the cloning from there? The new disk is basically empty save the new file system, but ofc I can just delete that.

Maybe I should start over since I still have the old disk. What would be the best/proper way to swap an older smaller disk for a new larger one?

No UUIDs, only paths. When booting from a live system I noticed /etc/fstab is empty. Also, there where a bunch of partitions on /dev/sda and I can’t see any on /dev/nvme0n1

No not consciously