It may not be an issue with the crickets. There are many reasons a chameleon may go off their food. Please fill out this form:
https://www.chameleonforums.com/threads/how-to-ask-for-help.66/ you can just copy and paste it here, and fill it out as best you can.
Husbandry issues and parasite infection are common reasons for a cham to go off their food. Posting a clear picture of your chameleon, and of their enclosure, can help too.