How to set the second pet?

I managed to get both reindeer and would like to run about with them for the holidays. But no matter what I tried, I always got my bear as the secondary. And when I stabled the bear, I got no second pet at all showing up.

What am I missing?

AC has a separate slot on the pet ui.
Do you happen to be over-writing it with some addon ?

I don’t think so, but I’ll check. I have to say the UI is changed quite a bit since last I used it, as I haven’t swapped out pets in years.

When I go to the stable master, I see four circles, then a minus/dash and another circle. Not entirely sure what that other circle is.

This particular toon only had 2 pets ever, these are his first new ones.

Put the Reindeer you want as your 2nd pet in the 1st slot of your stable.

I tried that. Didn’t have any pets in the stable at all, so I put the reindeer in there and still got the active bear. When I stabled the bear, the second pet is non-existent.