The flakes coming off, and the fish being new, I can definitely say this fish has at least flukes. If you look at the first pics, you can see the fish's dorsal fins are cloudy. Flukes are very common in angels. I treat all my angels for flukes, even if they don't show signs for it.
The treatment meds for flukes is PraziPro. It's claimed to be reefsafe, but I've only used it QT, and nor would I recommend it. You'll need to setup a hospital/quarantine tank. The issue here, is that your other fish, especially that Hippo I see, may be infected as well.