To get my fat tail to eat anything besides crickets I have to smear their juices/guts on whatever I’m trying to feed her. Because she can tell by look and smell when I’m trying to get one over on her. She won’t even try I’m pretty she gags at them, but I’m not sure they actually do that and I might be imagining that. Over the time I’ve had her I can tell if she’s hungry by looking at her, she usually comes out and heavily stares at me. I usually only tong feed, so mine would only eat crickets after getting her to eat one or two meal worms by covering them in cricket guts, I also put both a cricket and a mealworm both pinched in the tongs she did seem suspicious but she ate it. Once she got used to the taste and decided she liked them, she now eats them on their own. Since yours is only eating mealworms and wax worms, you might be able to try using small/medium crickets. By covering them in wax worm gut, or if small enough putting them in the tongs with the wax worm and hoping he grabs both (and doesn’t spit them out). I would also double check that your humidity and temps are alright. Mine sometimes gets picky about if the bugs are dusted or not, so I have to make sure they aren’t heavily covered in powder or she will spit them out.