| I would try to move it, possibly to a place with a higher or lower water flow; opposite of where it is now. I think that most mushrooms like to have moderate lighting and low to moderate water flow like my neon green variety. I placed mine in the bottom portion of my tank where it gets relatively minimal water flow from a powerhead that is bouncing off of the glass and it is doing really well and is wide open most all of the time which the lights are on. I had it in some higher flow areas initially and it was like yours and stayed closed up for the most part.
Hope this helps. I am new to all of this myself but learning a little bit, mostly with the corals I have bought so far though. | 
