where is it located in your tank? maybe start it off with some medium flow.
found this online...
Xenia sp. corals can be very difficult to acclimate; in general, cultured specimens are hardier than wild harvested species. Predatory fish (e.g., Xenia-eating angelfish), crabs, snails, or the stings of other corals may damage the colony quite easily. Therefore, provide adequate space between them and sessile animals, especially other types of soft corals. Some may prefer to be on a vertical surface. They require a medium to high light level combined with a medium to strong water movement within the aquarium. They have difficulty reproducing in an aquarium, however, some experienced aquarists have taken a section from the mother colony and attached it to a hard substrate with epoxy, and had some success. For continued good health, they will require the addition of iodine and other trace elements to the water.
They contain the symbiotic algae zooxanthellae from which they receive the majority of their nutritional requirements. Additional weekly feedings of micro-plankton or foods designed for filter feeding invertebrates are also needed.