I have a lone lyretail anthias (think it’s a female transitioning to male) that I’ve quarantined and had for close to a year now. She/he suddenly isn’t eating and is perching on the rocks a lot. Still swims around occasionally but seems to be breathing somewhat fast. Every single wet thing in my tank has been quarantined - all fish, inverts, corals. All other fish are doing great. It’s not too skinny at this point, it’s maybe been 2 days of not eating/lower activity level. Any ideas?