Pavona coral bubbling

[Bugenar]

Has anyone else noticed this? It’s been doing this for a little while, but it was on the right side, now it’s on the left side.

I noticed that the bubbling deflates, a small tissue piece is sloughed off and it repairs itself.

Camera quality is lacking but it’s literally just a bubble on the inside of the coral.

 

[bubbgee]

Might be an infection or a pest. Can you examine out of the tank? Sometimes it's a barnacle that made it's space there.