I can't seem to complete this scenario owing to being held indefinitely at a red signal just before the scenario end. It happens whether or not I have used Resume in the game.
You might have given up on this post as its about 10 days old but I gave it a go having read this and indeed I can confirm it's the same for me as you describe. Did you send off a ticket at all to DTG?
Have you tried pressing the Tab key to get permission to pass the signal at danger? If that doesn't work don't bother sending a ticket to DTG, that won't work either. They rarely fix bugs in broken scenarios.
I have exactly the same problem. Very frustrating Update: I have submitted a ticket - let's see if anything happens. Further update: I have had a reply and after a couple of conversations and submitting some screenshots they have agreed there's a problem and in their words 'the information provided should be enough for it to be reported as an issue'. Whether they will fix it, only time will tell. I shall update further if anything else happens.