Slipping rib or subluxation

Does anyone have a slipping rib or subluxation?
I can feel a popping/catching between my lower back left ribs when I quickly inhale or exhale. My partner can also feel it when he rests his hand on it.

I’ve been to two doctors and neither of them really tried to feel it, just diagnosed the costo but nothing further. They weren’t very hands on.

If you have, what does that treatment look like? Is it recommended to be using a back pod and stretching if this is the case?