I agree with Al about not seeing them eat. The only way to know would be to separate them and then see if there are crickets left. My grey tree frogs used to eat without me seeing them. They aren't shy any more though!
I don't know how agressive green tree frogs are and if the food is climbing on them and they don't eat it, I don't know if this would help, but for a while, I feed mine with bamboo tongs I got at the pet store.
I was afraid they weren't eating enough or that one was taking all the food. Turns out one's a female and just bigger. Anyway, I would pick up the crickets and wiggle it in front of them and they would grab it. They still head straight for the tongs when they see them because they equate them with food.
You might try tong-feeding just to see if they will do it. It works well if you have to feed dead food too because some won't eat dead food if it is lying in the bowl but will if it is waved in front of them.
Also, make sure the crickets aren't too big. I read they shouldn't be bigger than the distance between the frog's eyes, but mine have eaten them slightly larger than that. I buy them small but after I have them a few days, some always get big.
Hope this helps.
Diane