All chams at some point refuse a feeder item they used to eat regulary, it's how they got the reputation for being picky. I regulary rotate my food items.
Butterworms
Waxworms
Superworms
Crickets
Hornworms
Flies
Young Dubia roaches
Silkworms
The occasional kaydid, mantis, or grasshopper.
Parasites are a fact of keeping reptiles, regular fecals are mandatory.
Personally what you described doesn't alarm me but I'd do the fecals and switch out his food items to where he doesn't see any crickets for two weeks. He'll most likely be happy to see them after two weeks.
Hope that helps