When you state you have shut it down and re-started twice, were you referring to the entire aircraft or just the camera? Reason I ask is the camera has to be shut down independent of the aircraft to retract the lens. If you power off the aircraft without first powering off the camera the lens will remain extended. The same will occur if you power off the Pro Action without first shutting down the camera. I'm attaching two Pro Action manuals, one specific to the 920+ and the other written for the original 920 as they present somewhat different information that can be useful. Looking through the 920+ PDF the instruction for turning off the camera is on page 15 along with a picture of the controls on the phone app. In the original 920 version the power off instruction is on page 15 along with a depiction of the transmitter screen camera controls. The camera will power on when the aircraft is powered on but the camera will not retract the lens when the aircraft is powered off.
Check to make sure the JST camera connector is properly inserted in the bottom of the aircraft. Also note that if the camera is disturbed in any way during the aircraft power up sequence that movement can interrupt and defeat the camera boot up process. Remove the lens cap
before you power up. That's how I found out about interrupting the camera boot up process