Frogspawn coral receding

[DougiesREEF]

I am not sure what happened but my frogspawn’s tissue started to recede. My parameters have been consistent except my ato malfunctioned and my salinity dropped to 1.23 from 1.26. Attached is a photo it has been in my tank for 9 months growing very well. Should I move it? Does it do this when splitting?

 

[DougiesREEF]

Here is a top down photo you can see some of the white