Has anybody else come across these persistent barriers that prevent you from passing through them? I don't think it's like, a boundary for the world map or anything, because I can see other buildings on the other side of this barrier. I've also checked to see if maybe it was just somebody's claim that I was running into, but there doesn't seem to be any explanation. The only real reason I care is because I've founded a small settlement at the end of a river inlet, and lo and behold not more than 2 grids down the river before it intersects with any other bodies of water, there's this impassable barrier. Anybody know what's up?

The other members of my settlement are also having problems, it seems nobody from our settlement can make it through.