Nest of Bee’s projectiles gets blocked by lots of random things. Walls and trees make a little sense that they block the projectiles. The main thing that really sucks is Trading Outposts block their shots entirely if they are to close to them, and standing in a river crossing will legit cause all their projectiles to be blocked by an invisible wall.
It’s really weird and I don’t know if it’s a bug or an oversight or intended.