I use Z-1000s (and a Z500) at home and we use Z4000s on the Tracker layout.
I let the C&O orbit the layout on DCS today, similar to what I did yesterday. Also reversed the direction to that I was running yesterday. No issues and it ran like a champ.
I'm kind of surprised I can't reproduce this at home. I was (and still am a bit) convinced it was my engine since it did it at two shows in a show and was the only engine doing it at the show, not to mention my Rugged Rails F3 runs in a similar fashion on the Tracker layout.