I enjoyed reading through your debugging process and as someone who has been trying to debug a custom board for a few weeks now I feel your pain. I still cannot say that my issue is hardware, firmware, or software -_-
I do have some UART devices that really seem to like when I just disconnect and reconnect the GND wire when they start to act up.
I do have some UART devices that really seem to like when I just disconnect and reconnect the GND wire when they start to act up.