on us trains when coupling if your a foot away the train jump couples together. i guess it core issue.
You are talking about the Auto-coupling when it's set that way in the settings, or when you either do it on "foot" or fly cam? I have not seen this happen.
That is the same thing happening on the Boston Sprinter route now as well. There is a new scenario with the HSP release where you have to build your passenger consist and man, when you couple up to the other cars, it looks like a derailment.
i try on csx line with ac4400cw and sd40-2 and the sd40-2 didn't lungs at the ac4400cw when coupling. i guess that part of the updated Simu graph system.
File a support ticket, and include the video and all other info you can provide. That is just screwed up.