Is there a functional radius to a town center that the UI does not show us (yet)? I ask because I’ve got enough homesteads built that I should be eligible to move to Tier 3, however the count of available homesteads that the town center displays is lower than I actually have in my city. I’ve saved and reloaded the game a few times to ensure that’s not the issue. The only thing I can think of now is that for a few of my homesteads that are further away from the town center, perhaps they are not counted as “part of my city”?
Welcome to the forum. 
No, radius has nothing to do with it. Make sure that they are actually homesteads and not tier 1 shelters. Housing comes in different tiers - shelters, homesteads, large house, mansions and to move to the next one you need a certain figure of the current one: 25 homesteads to move to the TC to tier 3, 25 large houses to move it to tier 4.
Hey - thanks for the quick response!
I do think there’s a legit bug here. I’m aware that there’s a difference in home levels, and am 100% positive that I had more than the required 25 “homestead” class homes, but the town hall was still not lighting up as eligible for me. I still had some other requirements to meet (e.g. population) so I wasn’t expecting to be able to immediately move up, but the green circle indicating that I’d met the required 25 homesteads was not working as I’d have expected it.
I’ve seen a similar issue with several other “upgrade criteria”, like the number of herbs required, etc. There’s definitely something going on where it’s not immediately or properly showing that you’ve met the requested criteria at times.