I have one of the new SP AWTs that I have not run yet and so I am not aware of any quirks. I must say, however, that my previous Legacy AWT, when set up as part of Train, did not operate the way you describe with the coupler and back-up light issues but as the end of the combined units. (I am not a big fan of Trainlink and do not use it unless I have to, which I did not think would be necessary with an AWT.)
Like a lot of things, an operating issue of this kind might be cleared/fixed by changing the engine ID to something other than the default number or the one currently used. What I think of as a soft reset reset via the CAB2 remote key designated for that does not always have this effect. Have you tried resetting the AWT’s ID?
It never occurred to me that AWTs might be categorized as FRT rather than STM. I’ll have to check the manual more carefully!
