Diagnosis
That's the sound of the physical privacy shutter opening or closing. Yeah, it's jarring. It happens when you toggle the camera on or off in the app, or if the camera is rebooting/losing connection.
How to Fix It
If you're hearing it randomly, it means the camera is losing power or connection briefly, causing it to reset. Check that the power cable is firmly plugged into both the wall and the magnetic dock on the bottom of the camera. That magnetic connection can get slightly loose over time. Snap it back in firmly.
If That Didn't Work
The shutter mechanism itself might have a tiny piece of debris in it. With the camera powered off, you can gently rotate the outer shell of the camera (where the lens is) to manually open and close the shutter a few times to try to dislodge anything. Don't force it.
Heads Up
You can't disable this sound. It's a physical mechanical shutter moving. If it's clicking constantly in a loop, the camera is likely stuck in a boot loop and needs a hard reset by holding the sync button for 15 seconds.