I wanted to check with you if that's how it's supposed to be, and it's simply unfinished, or is there some kind of issue going on.
https://imgur.com/a/eJ2lckV

edit: I saw a comment suggesting reopening the game, it ended up solving the issue for me.
Before I solved it though I tried starting a game in a different location, it looked just fine, so I'm guessing the issue is connected to a specific tile pack...