kim_jorgensen what is your setup for compiling the firmware? which versions of gcc and cc65?
I'm using gcc version 9.3.1 and cc65 V2.18
That seem to fix it.
I added a compile time configuration option to change the devicenumber. Attached is version 1.14 with drivenumber 7. Will add it to Github and send a Pull request later on.
I tested it on my SX64 and it works for me fine, but no warranty