Beardie keeps jumping up and hitting tank lid
 

I've had my beardie for about 4 weeks now, he's 2.5 months old, 9 inches long. Starting yesterday he has started jumping up off his basking rock into the tank lid, repeatedly hitting his head. I have checked the temp of his basking area repeatedly and it ranges from 105-110 degrees, using a probe to take temp. Cooler side of tank ranges from 80-85 degrees. I have had beardie for years and have never seen any of mine do this. Does anyone have any advice as to why he's doing this? I'm afraid he's going to hurt himself. Thank you in advance for any help and info.