I will leave Dr_C and his expert eye to comment on the pictures. However, just in case there is no evidence of an obvious PCB fault, can I suggest a couple of things to check, just for completeness. Neither make much logical sense, but please bear with me :-)
1) I don’t think we had confirmation that the same problem happens when not using the app. Or, if it does, how the problem shows up without the error message in the app. I have seen this error message when there is not a short - typically when I power down the base with the app still running. So I think this worth a try, even if things seem to be working okay with the track power disconnected. Could you also tell us what smart device and version of the app you are using.
2) Neither have we had confirmation that you have swapped the controllers to see if the issue follows the controllers. With wired controllers, this would be an important problem-solving step. With wireless, it shouldn’t make any difference, but I would still try this to ensure there is no strange controller fault that we haven’t seen yet...
As I said, both are clutching at straws somewhat, but worth doing for completeness and removing any doubts. They might also help with looking at the PCB.