Goniopora is a hard species to keep in our tanks they do best in the wild
some have good luck some don't , on average they last around 6 months to a year
if it is already on the decline it is doubtful it will recover once the flesh starts to decline
there's no turning around ,
I had around 6 of them out of the 6 my first one that was like 6inch round open
it lasted the longest almost 11 months the other 5 all were a lot smaller and never made it 6 months , yes they are a beautiful coral and very delicate ,
they require moderate lighting and best placed high in the tank , they also like low flow ,