i had a nem that looked like this and it came back with me moving it.
i put in the corner of my bin, with minimal flow and light. 24" deep, under very little T5 lighting, with flow only breaking the water surface.
it slowly inflated and came back. once it "felt" better, it moved to more light and flow.
worth a shot to try in your tank if possible, or if you want to drive it my way, i can do this same thing to this one