To be clear the robot is driving, i.e. the RPi is getting power, you can connect to it via wifi?
There is no 12 or 5v on either of the auxillary connectors?
Are you getting at least 24v from the batteries?
There is a main fuse on the board, but you shouldn’t get any leds lit if this fuse is blown.
If you could take a photo of the board and LEDs when powered on, that would help.
Also see if you can get the results of rostopic list and echo of /battery_state ??
This sounds very strange. The only thing similar is low voltage, but in that case the robot would not drive, and you would not be able to communicate to the MCB.
Also, if you are equipped with an OLED display, what does it show?