Sorry Jim ,I am new boy to DCC. I have a EZ-Dynamis. I have 3 loco's , 2 of which have had conversion from DC and one new loco from Bachmann DCC ready, into which I have fitted the appropriate chip.
I programmed 3 loco's on service track and seemed to respond to instructions from hand held controller.
I transferred all loco's , one at a time , to main track, and they all responded correctly so long as only 1 loco was on the main track.
When a second loco was added, this is when the trouble starts. The second loco moves with the instruction to loco 1.
Any combination of loco's produces the same result.
Rgds
Bryan