This morning, going through the timetabled services for the 146.2. I decided to drive from Hagen Hbf - Wuppertal Hbf via the mainline. Hagen Hbf was busy with passenger trains and a passing freight into the yard, it was good to see it so busy! I got to Wuppertal Hbf, racing an S-Bahn on the approach into Wuppertal Hbf. I decided to drive back to Hagen Hbf on the S-Bahn, so I carried on in "Free Roam". I waited for the next S8 before taking over. It soon became apparent though that I was the only moving train. Nothing passed me going the other way and nothing was at Hagen Hbf waiting to go the other way. This is a bug surely? I was under the assumption that the timetabled services were meant to keep running.
I think it depends on the time of the day. What did surprise me a bit was the frequency of freight trains to be rather low. I'd expect to see a few more, to be honest. I was recently playing from 19H till 23H on game time ( yes... I've spent 4 hours straight on TSW, I was having fun ) and I've always had trains to drive from one side to another. I was guiding myself through the very nice timetable list online made by Marcus: https://forums.dovetailgames.com/threads/service-mode-timetables.18931/ - and his website direct link: https://smtimetables.herokuapp.com/
It was about 11am game time, so the map shouldn't have been completely dead like that. Which leads me to think it was a bug with the dispatcher so that it wasn't spawning any more trains.
But yeah I understand what you mean, I think I might have already experienced the same. To me so far it really just seemed like a moment "of break" without trains depending on the time of the day. But I can also be wrong...