Increase your salinity to 1.025 (but do it slowly). What are your other water parameters like? ie Alkalinity, Magnesium, Nitrate and Phosphate.
They are slow growing however spot feeding meaty food like mysis might help with growth. Can move if they want to by inflating and deflating. Better situated in the sandbed and not in the rockwork. Will shed off sand if slightly burried. If something happens and you think its dead never throw out the skeleton. Many people have reported new buds/polyps forming from seemingly dead fungia skeletons long after it had 'died'.
Congrats, it looks like mine. People are always asking me where I got it and if I can sell or frag it for them...
