Goni going downhill?

[will?]

Got a number of gonis in my aquarium, and recently my green one has been producing a brown discharge. Figured it was just waste since I increased my phyto dosing, but now there’s a grey discharge and same brown also that is sticking to the skeleton. Ive had a small amount of tissue sloughing off, and the skeleton under the grey stuff is grey and dead by the looks. Minimal damage to polyps, however the skeleton is mostly affected.

Cheers in advance