From the pictures, or at least the second pictures, it appears the coral is protruding its guts. I've had this happen to several of my corals and looks nothing like feeder tentacles. Most times its in response to a lack of food/nutrients. I've seen this displayed during the day and night, but like I said, it appears as a mass of white strings, filament like. Maybe spot feed both of those corals for a few days and see if that changes things.