buyed fishes deleted

Hello,

we've buyed three  buckets of Pufferfish and four or fife buckets of tropical fish with Emerald and put them in our lake.

yesterday we can't play  Realm, you know the problem why.  For a few minutes I logged in and 2 of the Pufferfish and all the tropical fishes are deleted. Why? A reconnection from a save (January, 6th) is failed, no safety found.

Is it a bug?