It isn't uncommon for ACFs to go off food for a while. I find it more common for males to do it than females, but it still happens. If your frog is still fat and acting normal, there probably isn't anything to worry about. You could try night crawlers as live food helps stimulate their feeding responses.
I do like to keep an eye on frogs that go off food just in case it is something wrong. Behavior will be the first indicator of many maladies.