For awhile during operations of my layout everything appeared to be fine, but after periods of running from inner main to outer main or loop to outer going over a 3-way turnout upon setting it to straight through caused the train to stop before it reached the 3-way. Resetting the 3-way cleared the problem.
I mentioned this to Paul at Trainworld and we worked though the problem and came to the conclusion, there's something wrong with the 3-way. As I'd a spare, I pulled it out and....



remembered that this was the 20~ year old 3-way that younger me tried to do something with on my old layout, as at the time I couldn't get my hands on insulated joiners and blah blah...

I think motion caused it to sink a bit on the foam trackbed and the loose wires touched, causing a short, the action of resetting moved the wires back to where the should be.