The second tier train does not carry out simultaneous unloading and loading

The second tier train does not carry out simultaneous unloading and loading

For small cars and locomotives, there was a station in the middle of the train with a refueling station in the center.

The train would arrive at the station, unload the first six cars, move to the end of the station, then simultaneously unload the last eight cars and load the first six cars.

Then I had to add another stop because I didn't want to overload the last six cars in this configuration.

With larger cars, this configuration broke down: the train would be completely at the station, but first only the last three cars were unloaded, and only then the first three cars were loaded.

Moreover, since the station now has a refueling station at the edge, not the center, the train would align crookedly, and the car would be half-loaded.

I tried swapping the station module and the refueling module, moving it from front to back, but the behavior was the same.

Even if we make a station and trains like the first option - with a hole in the middle - they won't be unloaded and loaded at the same time

This station layout for old trains worked so that unloading and loading occurred simultaneously in the second phase.

However, when I completed the refueling station, trains began parking one platform further back in the second phase, and the central car wasn't refueled. However, after pausing, the situation improved.

But I can't replicate this behavior for the new stations.

P.S.: When I first started building this line, I expected the train to travel around the station twice and complete three stages of unloading/unloading + loading/loading. However, I had to add the station again to the list to prevent the train from leaving with empty rear cars.

P.P.S.: On the diagrams, short trains have their front cars on the left, while long trains have their front cars on the right (they are loaded with fertilizer II) - perhaps this is the reason.

I excluded the train's refueling - the behavior did not change

https://drive.google.com/file/d/187oFadEqYS23LiuXDDibGHzl6FUXwZQJ/view?usp=sharing

I tried all the options for mixing long and short cars, but it doesn't work as before.

If you combine short cars and locomotives into a train, it also doesn't work as before. What happened? Was the locomotive in the middle the key to the simultaneous loading and unloading system?

upd: also don`t work