Make sure the food dish isn't too large. They only eat a very small amount, a few licks. Its very easy to miss if you feed a lot of food. I use beverage lids about the size of a milk jug lid. If you have a soil substrate, cover it with papertowels for a couple weeks (its easier to see poos). If you see poo your crestie is eating.
As for the not sticking anymore, your crestie may have some stuck shed. Mine shed quickly, its very easy to miss. You can try a "sauna". I use a tupperware type container with some small holes in the lid. I use lukewarm water, very shallow. Then I leave the crestie in there for about 20 - 30 minutes. When I take them out, I GENTLY rub their feet with a wet q-tip.
Our children are our legacy. What we teach them is what we leave behind.