Here is part of the reply from ring.
"We think it is most likely that you are getting low voltage detected by the module. The reason why you may not see it on the loco info page meter or on a DC volt meter is both of these displays are heavily filtered (take some thing like 1 second to respond to voltage changes) but the low voltage detection in the RailPro module is very fast (can detect something like a voltage drop for 0.05 seconds). So the module can detect a brief interruption in the electrical connection that a DC meter or the HC info screen would not show."
In my opinion, if the sensitivity is that high ,I'm just chasing ghosts. I am going to try to improve the pickups the best I can and go from there. If I figure something out I'll chime in and share my findings.
out of curiosity, what are the model numbers of the locos?
Model #s are 94754 94752 98061 and an SW 1500 I can't find the box for.
All 4 act exactly the same. Never in the same places either. Just out of the blue. I'm not gonna rip my last 8 hairs out over it after I fiddle a little more.
Thanks for the input and suggestions.