What lighting do you have in your tank? How big is your tank. Anemones will move to the perfect spot for them. If your tank doesn't have enough light they will continue to move, which isn't good. When I introduced my rbta into my tank, it moved twice.
I read some where that if the tentacles are long and not bubbled that they are recieving enough light, when they bubble their tentacles that means they are trying to get more light.