Frogspawn help

[Ipyloves]

Not sure whats going on here as it has been doing so good. When the lights are out all of my coral retract but this bubble on the mouth looks like something is wrong

 

[EeyoreIsMySpiritAnimal]

Looks like it's pooping

 

[BonnieB]

How long has it been doing this? Only at night (if so I’d agree with pooping)? What are the parameters, lighting and flow like in the tank? And what is the age of your system (looks relatively new)?