I have the same issue. The guardians literally float in mid air indefinitely. I've changed the size of the drop shoot and tried 2x2, 4x4, 4x6, 6x6, no change. I've changed the material from glass to prismarine to blue ice, no change. I've even removed the blocks and they will float around the room. I hit them to knock them down, no change. I finally installed dispensers with lava to clean out the floaters in my drop shoot every few minutes. Spawn rates on Bedrock are awful normally, this sucks.
This happened to me using Realms. I played a little on Xbox on the morning after the update dropped, all good. Logged in with Win10 at lunch, spawned as a new player, naked with a map in my hand at world spawn. Nothing else in my inventory, and even worse, nothing in my ender chest. All my shulkers full of gear, prized possessions, etc.... gone. And now, when I make a new map, my personal map counter has reset as well. All my achievements still on record. My local game/world is OK. Why didn't I try a roll back to a save? Didn't know for sure it would bring back what I lost, and my wife was draining an ocean monument and had laid sand walls and sponged water all day. A lot of work to risk on a roll of the dice.
Oh, wow. I'm stunned. Logged in today, found 2 chests with all my lost stuff. Thank you!