Pac-man frog, what am I doing wrong?!

Hello all! I purchased a PAC man frog from a vendor at repti-con ATL to replace my daughters leo we had to put to sleep the week before. He was kind of an impulse buy because I was actually thinking about a bearded or BTS but I'm familiar with them because my uncle had them when I was younger. I brought the little guy home and set him up in an old plastic fish tank w/ sphagnum moss that is pretty damp but not saturated with treated water.
My issue is this-the frog seems healthy, moves when I mist it, skin looks good but I almost have to force feed it to get it to eat. I raise Dubia roaches so I've got a multitude of sizes and I know they're ambush hunters but I tweezer feed in order to keep Squooshy from consuming a lot of substrate. I basically have to piss it off to get it to open it's mouth & then it seems like it's trying to use is front legs to try to brush it out of its face.
Any tips? What am I doing wrong? Thanks so in advance for any help!
Dez

Maybe it doesn't like dubias. Have you tried crickets? My pacman will not eat dubias, he also doesn't like to eat when someone is watching. He also uses his front legs to push the substrate from his mouth. When I first got my guy, I fed him in a different tub just to avoid the substrate issue and to be sure he was eating and he would gobble up all the food I put in there, except for the dubias.

That's what i was thinking-he seems like the legs bother him. I'll go grab some meal worms this weekend and try. Also,, thanks for the info about pushing the substrate away and someone else had recommended a feeding bowl. I wasn't sure since they're ambush predators how that'd work but from what I've read it works really well if you're worried about them eating substrate. Thanks so much!!
Dez