Blonde Naso Tang

So in my quarantine tank I have a blonde naso, a fox face, and a yellow tang. I am at just over two weeks in the quarantine with them. The fox face and yellow tang seem do be doing just fine. The blonde naso has been eating/swimming and looking good since i put him in quarantine. Today when i got home from work for the past few hours he is just laying on his side. I checked all parameters and they test great but just to be safe I did a water change and turned out the lights. My qt is a 30 gallon. Any ideas if he is just stressed or i should be doing something else? Should i move him to my display tank? I just figured that would really stress him at this point. If i hide an watch the tank from around the corner I see him move a little bit to different spots in the tank but when he stops he falls to his side.