Hunter pet stuck in unbought, second stable slot

WoW Classic Hardcore - Defias Pillager

Class - Hunter

My pet (owl) is stuck in the second, unbought (5 g) stable slot. I had just bought my first stable slot, place my owl in my second stable slot (some how) and unable to interact with it now. Need help!

While I’ve never talked about this with anyone else, I had assumed this was just how it works. You are able to stable the pet, but not release it until you pay for that spot. That way you can still collect more pets.

Is this not how it is intended to work?