I built a squid farm at y 110 above an ocean monument, it's a 20×20×2 pool of water. I used bubble columns and boats to get guardian in the pool and once it was in there it just tried to constantly swim down ignoring both me and the squid. After watching the guardians in the ocean I'm pretty sure they're AI makes them swim down once they hit a certain y level near the surface of the sea and because the farm is above that the guardian is stuck searching for a way down. I caught the guardian tryin to swim back up the waterfall that led to the pool, I removed the water but the guarian remained in the air. I hit the guardian with my hand to knock it back down but it just swims back up out of the water and behaves as if the waterfall is still there trying to swim up what is now air blocks. So now it's just stuck in a swimming animation floating a full two blocks above the pool with it's spines rapidly expanding and retracting.