I got this guy a few weeks ago and he was big and open and full of life. Last night he moved and went to the other side of the tank and the a few hours later I noticed him all closed and he wasn’t attached anymore, but in the back of the tank balled up. He was completely closed and not attached. I moved him to the front and he has attached himself in the sand and to a rock and opened up a little when the light was on and has now started to close again. Here is what he currently looks like. I fed him yesterday and he was fine.
I really don’t think you are going to get enough ligh from that fixture to support an anemone. They are great for softies and LPS not as good for SPS or anemones. Your tank is deep. If the nem was near the surface maybe. What you are describing is the slow starvation caused by inadequate light.
I use Kessils. I have 4 on my 5’ long tank. That is barely enough for an anemome and only near the surface. My tank is deep also. The Kessil 360 Narrow May be something you can add to get light deeper. You might be able to use a second Maxspec. You could even add some good quality T5s, maybe 2, 2bulb fixtures to what you already have. I can’t say for sure that will be enough to save it. Or support a new one.
Deep tanks are always a bit difficult to light.