GGG- when I serviced the engine I had jumpers clipped to the roller bracket. I tried each independently and they both worked. I pulled the pick ups and cleaned them both after the issue arose, no difference.
I have 036 fasttrack that I use at Christmas. I'm going to set up a loop with a switch on the floor and try it today. If the engine works then it's track related. I do have other MTH engines and they cooperate with the 027 track. If the same issue persists then I'll have to dig deeper into the trucks and wiring. I do have two 042 switches on the layout and the engine does the same thing on them.
Here's a video I shot after repairing a broken speaker wire.
Thanks- Bob