These folk ain’t kidding re wacky behavior!
I have a stichodactyla tapetum that I loved observing every day. He was fine on his initial perch for months. Then one day just over a month ago it moved to a super shady spot in the back of the tank near where my clowns sleep. It looks full, healthy, and vibrant and reacts to things (even caught a shrimp that was bothering my duncan).
I was worried until I read what others said. And so there it has remained. He moves a little to the left, right, or higher, but not much. I’m thinking he likes the flow and gets enough light to be happy where he is. Plus I can’t really relocate him without hurting him, so just have to let him be.
I wish you good luck and health to your creatures.