So I started a new city new to a coal mine that had just started. The workers at the coal mine were all from a city that, while the nearest city, was quite far away.
In previous versions of Simutrans the workers would shift to the new city, if one was started nearby. I've played several game years of this version, my new city has grown considerable, but all the workers still work in the original city.
Is this a bug? What do I need to do to go back to the old behavior of past Simutrans?