@Arnold D. Cribari I have a similar subway set and have no issues with it. I have to agree with GGG on the board or programming as being the most likely issue. Unless you want to try loading the correct file, I would take it in to be re-programmed. To me that might be the most straightforward fix.
The engine being read is an Amtrak Diesel, so someone likely was messing with the files. If the gearing does not match the flywheel tape, you would get different speed readings for on layout speeds. Speed is read from the tape speed (flywheel rpm). I expect MTH software calculates scale speed by using this variable input and a known value for a particular engine. But the MTH service techs would know this way better than I do. I can think of a couple of other possibilities, but don't think those are likely due to required effort.
