Ring Stick-up Cam Elite, error P1-81

I have three of these cameras and all were working yesterday.  All are connected via ethernet cable via POE.  Now without any changes, one of my cameras is offline.  The error details say 'error P1-81'.  I reset the camera with a 30 second hold on the button.  After 30 seconds of blue light on, the blue light flashes a few times briefly, and I get the 'setup your camera' audio line.  Then, immediately after, the light goes red and I get a 'unsuccessful' audio message.If I leave the camera alone, it repeats this sequence basically forever.  I have to unplug the camera to stop it.  Can anyone help me?