What type of lighting is it under?
FWIW, the meals you are offering it should be small chopped even minced and administered with a turkey baster type utensil.
The reason behind this method is, the food is meant to aid in the recovery of the animal by giving it added nutrients. Consuming a large meal takes a lot of energy for an anemone. So it the added nutrients is lost in the process of consumption and digestion of a large piece of food. Where as chopped or minced food is very easy to consume and doesnt take much energy at all to do. The anemone will benefit from the nutrients while not expending all of its energy on digestion and consumption. HTH.