Hello, I have noticed that whenever I try to build a new town after building a first one, I can't grow the new town manually by increasing the population. I thought it was an issue with Pak. 128 Britain, but I tried it with my pak. 256 America that I'm building and it's the same issue.
This bug has been reported many times in the past.
I have already mentioned the cause and countermeasures in this thread (https://forum.simutrans.com/index.php/topic,19719.0.html).
Correcting the wrong formula will greatly improve the symptoms.
Ah, I didn't know it was already mentioned.