![Image](https://forums.factorio.com/images/ext/bb8f50e398b6b020683165baac9fce9f.png)
Steps to reproduce:
- Download the attached world
- After about 10 seconds, an iron train leaves the north station, the southmost train moves from the stacker into the now empty north starion.
- About 10 seconds later, a train leaves the south iron startion, resulting in the exact situation from the screenshot.