Red signal aspect due to other schedule trains in station after you complete boarding and no way to pass by.
I have the same problem. I think that the train is on the wrong track because you have to open the right door not the left door.
If you spawn on foot at 21:45, you can take over the service when it actually starts a little after 21:51. You are able to complete it this way. Just be sure to turn ACSES off until you are clear of the tunnel, as it will show a restricted signal at 20MPH the entire length of it.