Isn`t this like your second or third thread with the same topic ?
Anemones need pristine water , a well established tank , medium water flow , and medium to high lighting . How old is the tank ? How long have you had the nem ? How did you acclimate it ? LTAs need at least 3 inches of sand for them to bury the foot in .
Usually when an anemone does not settle , something is wrong with the tank and it can not find a spot it likes in the new surrounding .