I don't have my camera atm and I haven't been able to get a good shot with my phone but I think it's coral stings cause in the morning I found my trumpet coral in my powder blues sleeping space, plus it was literally an overnight thing, before lights off he was perfect then in the morning one side of him had white spots.
He's acting normal, eating like a pig, and I noticed he's not scratching himself, I've seen fish with ich scratch themselves against a rock or something