Mine do great under my Kessil 360 we's. Watch where you have your intensity set. They are putting out more than your eyes lead you to believe. I found that out the hard way.
Since you only have two settings be sure to start the coral low and work your way up over a month or two. Looks like it's just bleached to me. Also water parameters would help identify any other possible issues.
I don't think I havegood enough lighting. it is a beams work and I don't have any idea how old it is. For a 55 gal what light can you suggest? I looked at the eccotech radion xr30w but I seriously know nothing about shopping lights...