You should post issues with beta firmware on the Raspberry Pi forums, since you'll get better support there. If you want to get back to a working EEPROM, I suggest you use Raspberry Pi Imager and flash the latest stable EEPROM image.
Hello, I was looking into the firmware flashing options too for my Controlblock. Have anyone tried to flash with Arduino Uno as ISP or with the Arduino Nano Every?
As I have both it would be the fastest but I would love some help to do it right...
Hey I am having the EXACT same issue. So did you Filezilla in and remove the extra "input_player_1" entries? Ive been messing with this since Saturday. I also had this issue with an afterglow xbox 360 controller.
Pi: 3 B
RetroPi: Latest 4.0 build
Controller: NES30 Pro