If I’m understanding correctly when you selected run my trains, you get power to the track. Without having added an engine. Correct?
You shouldn’t have power to the track until after you add an engine to the app or select an engine that is already in the app.
I find it helpfull to have a lighted car on the track when I’m trouble shooting. It indicates when you are getting power to the track.
This is happening with either of the trains?
I would try taking a couple pieces of track on the side, connect the Explorer and attempt add each engine. This would eliminate the possibility of a problem with the DCS signal running through the track.
Mark W