Yuma or Florida? I keep yuma.
They hate Vibrant ( have you been dosing any?) and large additions of magnesium ( high mag is fine, then just don't seem to like it added all at once).
They prefer lower lighting and flow. They need nitrate and phosphate in the water but usually not as dirty a tank as discosoma or rhodactis like. They like food. I feed mine once a week Vitalis LPS pellets but any meaty food is good if they can fit it in their mouth.
A list of your tank parameters would be helpful.
One of my yumas that I happen to have a picture of: