I have repeated this multiple times today - when doing the Snow Time Scenario on HRR in Journey mode, shortly after departing the first station (a few yards) the traction lock kicks in if you have enabled the safety systems. You can only depart if you are not using SIFA or PZB.
Works OK for me (PC). Try to stand up and sit again at the very beginning Acknowledge starting program after departure (don't know, if mandatory) I do it. BR o7
I'll try the stand up and sit down in a bit then (seeing as it puts you straight in cab) - Strangely, the stand up and sit back down fixes it...