replied from the actual city

Another hint for who need to know: have the SPRinters that can go on any platform switch to the other side of the two rails before entering the platform, as the InterCity there arives later and won't be blocked by it after it leaves the station.

Well, I don't see a way of completing it.

To help clarify, there is indeed no Oss 3, and Oss 4 is merely there so it allows me to make the freight train work.

(Also I said loosely based mostly due to the switches not being perfectly accurate, but that indeed also goes for this non existant platform 4, which in the irl station is just some rail used to park cargo.)

Also, to give a hint try playing with auto accept on on the stations. That's what I used while testing (and got me a perfect clear).

@Larkspeed I haven't downloaded the map, so I can't check if the screenshot is accurate to what is in the game.
But if the claim that this map is (loosely) accurate to life, then there is no OSS 3 intended to be there.
OSS 4 existing at all, based off Google Maps, seems like a concession to players.

Kept running into jams because OSS 3 is not labeled so trains don't see it as a viable stop