as I get the instruction to uncouple at Minehead (after the trip from duster). when I uncouple the scenario doesn't progress and I'm stuck. I've tried this 3 times all on xbox 1s
You have to wait until the passenger doors are closed before uncoupling. The instruction to uncouple appears at the wrong time, i.e. 10-20 seconds before the doors close, but if you uncouple at that stage it breaks the scenario.
