I hope this helps. If the tamer present to your character is part of an expansion's "Family Battler" engage it accordingly. For example; currently Faryl from Ardenweald/Shadowlands expansion is available at the celebration grounds so get you best "family" team (dragonkin, humanoid, etc.) & you will...

This does make a little sense but I've seen ones that I've battled before and then I can't. Are you unable to battle many of the pet battle masters? Thanks for the reply. I had been really gnawing my craw lately.

I have a couple accounts. On my main account I had been able to do the Pet Battle dailies at the Caverns of Time Anniversary event, but I am no unable to do so. What is going on there. On my other account, I though that I had maybe accepted a quest but not sure if i finished it, the 2nd account does...