I have the Node 1+2 eMMC flashing issue (3+4 work). Likewise, I had keyboard issues with the red/white Raspberry Pi keyboard (https://www.raspberrypi.com/products/raspberry-pi-keyboard-and-hub/) and when my keyboard was connected via the monitor (Dell U2412M) USB hub. However, when directly connected, Logitech K120 and a WASD keyboard worked nicely! Edit: the above is for Raspberry Pi OS (Lite, 64bit). Did not find a Keyboard working with DietPi.