sounds like lighting if its opening at night under the lower lights, it might be too bright for it open up all the way with the day lights on, my finger leather did that untill I place it under an overhang in my tank...super clean water too, more softies like dirtier water than
sps's..like the gonipora, most die within a year but they come from lagoon type areas so the water is dirtieror higher in nutrients then open ocean reefs