I'm not sure you have your probe in the right place looking at the pic. I like to go in horizontal from the end to the thickest part. Have you checked for probe tender?
Weber WSM, Weber GA, Weber Spirit S-320, Weber 22" OTG
Charbroil Oilless Turkey Fryer
Wife LuzziAnn 1956 model.
Maverick ET-732, Superfast LSU Purple Thermapen & ThermaPop, Party Q