Leathers can be pouty sometimes. I have never kept one but have talked and read about those that have and its fairly common to hear that they can remain defalted for days or even weeks. It is entirely possible that its in one of those stages and that typically leads to the coral shedding an outer layer (which you should remove BTW).
The other thing I see in the pic is that shroom laying on it which may be irritating it. Softy on softy shouldn't be too much of an issue bit if there is an easy way to move the rock the shroom is on I would.
How is the flow in the area the leather is in? They like a decent amount.