Hi guys. Been struggling with this problem for several weeks now. I need to flash some 32u4s with an AVR bootloader or at least change some fuses so I can use the DFU one installed from the factory. I originally tried using a Pro Micro as an ISP programmer but that didn't work, so I sucked it up and bought an AVRISP MKII thinking the Pro Micro was my problem. However, this still doesn't work. The furthest I can get when changing fuses or flashing a bootloader with avrdude in a terminal is a device signature that does not match the expected one for a 32u4, and it won't continue past that. I would post the signature here, but it seems to change to something completely random every time I re-run the command. I've tried on four 32u4s and two Pro Micros and they all had the same problem. I also tried with the Arduino IDE and the "burn bootloader" function, however, that didn't work because it only uses port "usb" but I have to specify /dev/ttyUSB0.
My wiring is correct, it isn't something stupid like a broken USB cable, there has to be a problem with either the programmer, avrdude, or my computer. I'm running Arch Linux, have not tested on another OS as it's not something I can do at the moment. I should also note that I removed modemmanager a long time ago and that I can flash Pro Micros with code both through avrdude and the Arduino IDE with zero problems.
Any help is appreciated because I'm losing my mind and this is really pissing me off. Thanks!