It's not the town.
There's a bit of an odd, random glitch where fresh sims cannot learn certain skills. The big one, in my experience, seems to be athletics. However, I never had a problem with it until after I got Late Night, so I'm firmly convinced that it is somehow related to the vampire glitch.
This glitch either happens from the start, or it doesn't happen at all. And once it happens, the only way to fix it is to start over from the beginning. In the case of former vampires, you need to revert to a save when they were still a vampire and un-vamp them again (always save just before you drink the potion). The last time this bug hit me, I had to restart 6 times before I was free of it.
The easiest way to test a new game for this bug is to send them to the gym first thing. If their athletics increases, you're good to go. If it doesn't, exit without saving and start again.