Dogs Despawning in Peaceful Survival

Your username: LizzieRa17
In which minigame/server does the bug occur: Peaceful Survival
Detailed description of bug: I had two dogs (both tamed with nametags) that were sitting in my base. I was very sure that they were both sitting and not following me. I left the server and had been on and off for about a week. Last night saw both of them still where I left them and the only member of my faction that was online since then says that she also saw them sitting where I left them. This morning both dogs were gone, almost as if they despawned. I have made sure that no one in my faction has moved or killed them and they are nowhere to be found. Also just a few blocks away from them were my friend's dogs who had not disappeared. I have come to the conclusion that it must have been a bug and hope that either two nametags or $2000 could be given to me to make up for the nametags that were on the dogs. Thank you for reading.

I unfortunately have no evidence because I had not taken any screenshots of the dogs prior to their disappearance.