Do you have a Cab1 just curious if you have the same problem using it. I wondering if for some reason there not receiving the signal correctly. You said you tried a reset. Wondering also if the antenna in the engine is receiving the signal there all 3 rail wondering if there may be a problem. The second set does not seem to be a motor problem as you can get them to run.
How about a complete reprogramming. Make sure nothing is on the tracks when doing so. It should not be a problem but have come across with TMCC where it was. I even had one off the tracks but sitting right next to the track and a problem because it still had some power from the 9V battery. To be honest with you I had the symptoms of the first engine one time when I needed to replace the batteries in the cab1. But do not believe this to be your problem.
