Well I'd kind of agree, but it's Roco and Digitrax it fails to work on when loaded, works fine light engine.
Swapped out the motor/gearbox and with the same settings now works perfectly with Roco and ESU, I've no idea why or what could be the cause.
I can now auto map the motor/gearbox with CV54 =0 can't do that with the original, just sits there and then refuses to run afterward, the only way to get it to run is to reload a stored backup before auto mapping.
I've fitted a dozen or more Maxon 10W motors over the past couple of years and I've never seen one this big; I've a feeling the kit has been languishing for many years before building so the motor may be a very old one ABC no longer supply. It may be one of those that has DCC compatibility issues, either way it's to unreliable to fit in the customers model.
I have another VML2 with Maxon 10W and a Mini with a Maxon 10W I could try, but my gut feeling is they'll work just fine.
Addendum, it auto mapped once and now refuses to do it, to be fair I have struggled doing that sometimes, so maybe something I'm doing on reflection, but it does now run smoothly on both controllers under heavy load.