This may be due to a dislike in the food you are providing... The BD that I care for doe the same thing but that is during hand feeding as he has a few screws loose due to a poor previous owner. The BD I have to hand feed will not eat pepper (of any colour) nor leafy greens. I found I can only get him to feed on grapes, carrot, sweet potato, and sometimes mango and papaya.
Keep trying a variety of different F&V.
Also what vitamin supplement are you dusting the F&V with as some taste bitter and the animals will also spit them out. What ever you are using simply dust the food very lightly and allow it to soak in before feeding so it almost disguises the supplement.
I hope this helps.
Also btw... the smaller and more manageable the size of the food is the more success you will have.
2.5.0 Eublepharis macularius
1.0.0 Pogona vitticeps
1.0.0 Mesocricetus auratus