I’m afraid I didn’t quite understand your hardware setup. Could you clarify whether you connect the Navio2 UART port to the Reach M+ S1 port or Reach M+ USB port?
If you could send the photos it would be very helpful.
The full system report can be downloaded from the Reach. It contains logs about the condition of all parts of the system. For example, you can share it with me so that I can check out the temperature of the unit.
The UART port is always powered. However, if Navio2 isn’t provided with sufficient power itself, it won’t be able to provide enough power for the UART port.