I noticed my trains doing this on the server game and reproduced it in RC 11.9
When the train heads away from the depot, crests a hill and is about to enter a curve, it will stutter. This is despite the game itself not stuttering.
When you write that this can be reproduced on the server game, do you mean in version 10.27, or on a saved game loaded from the server in the RC, but not in 10.27?
I first found it in 10.27, but I reproduced it in a fresh RC 11.9 game by copying the track layout.
Hmm, I think that I have just seen it, too. Looks like a physics issue. Bernd - can you investigate?
I fixed this physics issue in my 112.x-private-cars-merge branch.
Splendid - merged.