Tropical fish are disappearing

Cannot confirm. Was the tropical fish naturally spawned, with a spawn egg, or from a fish bucket? Did you rename the fish using a name tag?

Spawned with a spawn egg. Yes, I renamed the fish with a name tag. Sorry for taking so long to reply....

Same exact issue. Whether I name them with a name tag, or name them by 'renaming' the bucket on an anvil. I dump them in an aquarium, and after an hour or so, they're gone. I assumed someone was just messing with me on the server.

(So far, I've lost about 30 fish that way - all that xp in renaming, down the drain...) The server, if you need to check it out there, is Catcraft.