As shown in the pictures the auto petter and collector are moved in the underwater barn whenever I save the game, close it and then start it again. They are moved into the bottom right corner. I had them mirroring each other. As shown in one picture the moved object is still located in its original position, and can be axed there, and also only interacted with from there.
This bug also caused the Mermoo in the first picture to get stuck between both objects and it couldn't leave the barn after they were called out.
Another bug I encountered was that the underwater barn animals don't wander as much as the land barn/coop animals, even though seaweed is technically in range, therefore leaving the (underwater) animals cranky.
I don't know if it is wanted, but the underwater barn also disappears when the player hugs the doorframe of the barn doorframe.
I recently started playing Coral Island again and those were the bugs I could think of regarding the underwater barns currently. I found some clipping(?) when walking over stuff where it looked like I should be able to walk over, but I don't know if that's important to report, and it's not that report, since one doesn't get stuck
Edit: I also noticed that the ring to improve swimming speed doesn't always improve the swimming speed, and I have not seen any way to figure out what triggers when the speed improvement gets triggered and when not.

