Not really, try to keep it well fed, but it's well documented that these can nip at coral.
That is your problem. That tank is too small for an Angel fish. He is under stress and just reacting to his enviroment.
A coral beauty will never work in that small of a tank. Period. Even in larger tanks they will eat corals if given the chance. I have kept them for a number of years and even when well fed with algae they are at best a 50/50 chance of not going after corals. Please, please find this fish a larger home. Maybe find a better LFS to deal with as well. There are a number of equally attractive fish to be found that will stay small and do much better in your tank long term.