I used this guide: Ultimate Guide on Using Trezor on Qubes
Instead of a whonix AppVM, i used a fedora based AppVM.
I already deleted the file created in dom0 under the second step.
Another thing i did was the suggestion from the Whonix docs to try a separate HVM persistent Qube. One controller threw me the ‘couldnt reset device’-error, so i forced the reset via the Qubes Manager GUI under Qube Settings→Devices→bottom.