Yeah thats exactly the problem. One is a 123, other is a 163. I'll go switch that up right now.
Are you using a DH123 and a DH163? If so, the problem is one has BEMF and one doesn't.
Give CV57 a value of two for the DH163
I tried (and failed) to mu two of my GP38-2's. Both are equipped with digitrax decoders, one is a two function and the other is a six function. When I went onto my zephyr to program the MU it worked successfully. Once I tried to run the consist the problem occured. Despite that both engines had the same speed setting and both were from the same manufacturer (Athearn) the lead engine barely responded to me working the throttle while the trailing engine responded fine.
Any thoughts?