The actual radar sensor is the black box looking thing mounted right behind the sombrero. I don’t think there is any kind of “lens” but it’s position and any angle up, down or sideways affects where the radar beam goes. Yours might be pointed more right than it should be. There is a calibration procedure in the FSM but it’s a little complicated and I think requires some kind of special targets. A Dealer can do this for you. My dealer initially refused to calibrate it due to my aftermarket bumper and lift. It’s the lift that makes dealers not want to touch the radar cruise for liability reasons.
I’d be tempted to just mess with the adjustment screws and with trial and error see if you can make it better.