Oh, you are right, there is a station I had forgotten about in the middle of the map. It's set to 0 train limit which explains the train behavior.

I've discovered a possible issue with the station counting mechanism.

https://imgur.com/a/S7TIIW4

It reports 3 stations, but I only have 2 stations with that name. (middle top & bottom right of image 2)

Trains seem to properly respect that there are only 2 stations.