Mushroom STN / RTN in soft coral?

[The Mushroom Man]

I’ve been monitoring this mushroom for about a month ive notice the top of it was turning white and I figured it was because it was bumping up against the gsp, even though im not fimilar with gsp having stinging abilities, fast forward to today its now definitely receding, i have another one on the other side not even touch the gsp doing the same thing now, What is this some sort of stn / rtn ? Does that effect soft corals im familiar with it in acros and montis.

 

[exnisstech]

Not much help but it'll bump this for you. I've not heard of STN or RTN on softies. I have heard of gsp irritating other coral but have no first hand experience as all of mine is not near other coral.