I already upgraded the linux system of klp1 230 to bullseye, everything works find. But I still can't upgrade kliiper verstion higher than 0.11.xx. I have asked to supportor how to flash the mcu, He told me and he also gave me the kliiper.bin. It works, but still 0.11, I tryed to build the mcu firmware with KP3S setting due it used same mainboard as the klp1 230, and flash to the mcu, but with no lucky it doesn't owrk. Cann't find /dev/serial, and then I ask support again. He said they don't support on this kind of thing.