It’s actually quite complicated and I did “simplify” some things. Like the train was already over the border. It’s the German/Swiss border … but there is actually a German railwaystation in Switzerland. So the train stops in German customs territory (in Switzerland) and you have to go to “border control” to exist the station. It was there that the train was held up. But I don’t even understand how that works exactly. Like Switzerland is not in the EU but it is part of the Schengenzone, so you have “free movement” … who knows how it works.

So yeah, I “skipped” all that. In the end, the trained needed to be stopped for this important matter to be resovled.