I had a weird issue similar to this. When I charmed a jaguar, its name changed to the one I had given my alpine wolf. When I switched back to the wolf, its name returned to the default juvenile alpine wolf. I renamed them both and it seemed okay after that.
I haven’t charmed another pet since then; if it happens again I’ll update this post.
Edit: It happened again when I charmed a new pet. Filed a bug report, hope these issues get fixed.