despawning villagers and cats

8/19 entire village of villagers de-spawned including tamed black cat. I ended my session. A few hours later I logged in and all the villagers and my favorite cat- gone.

Previously villagers and cats have been de-spawning in the seemingly randomly one or two at a time. Now, de-spawning seems to happen more frequently.  It seems as if de-spawn happens mainly in village I am in or cats I am with.

Tamed wolves have duplicated.

Collar colors have changed.

Because I am a very new Minecraft player, I thought it was something I was doing. However, I am not new to gaming.

Thank you for your help.