Incredible Hulk coral white recession

[Brinley123]

Not 100% this is an incredible hulk favia however any idea whats happening with it please, its where its been lay on the rock as the frag was conpletely covered both sides? Also is placement ok? Im happy with the flow, thanks in advance and apologies for the poor pic quality!

 

[Brinley123]

 

[Brinley123]

Ive just given the coral a blast with the powerhead and moved it to low light, looks like the area where the mucus was is dead!