As someone who just had a very, very poor experience with a new frog being stressed out, I would just suggest to leave him be. When I took my frog to the vet, they emphasized that its more about weight loss than eating or not eating. From what I hear, a lot of frogs take weeks to adjust and to feel safe. So if he doesn't look like he's losing weight and isn't visibly sick, I might give him some more time to come out of his (literal) shell, haha. I was a helicopter mother to my frog when he didnt eat, which ended up making him more immuno-compromised than he already was. I learned my lesson the hard way, I would hate for anyone to go through the same thing. =/