Happened again for us last night. We were sitting in our living room and got the message that motion was detected at the door. I opened the door and nothing there. On video it shows the weird orb.
There's discussion of this issue elsewhere at the board, remains a mystery for the moment.
I noted a static ghost/orb this evening on mine (wired video doorbell). Location is under porch awning adjacent to door, side-lite window, and under a coach lamp. Coach lamp presently sports an LED bulb. Earlier period of constant floating ghosts corresponded to a fluorescent bulb. Blinding the coach lamp - or simply shielding the doorbell - makes the ghost disappear. Cleaning the camera lens did so too (but failed to eliminate the reddish ghost top center). Curious whether others with this experience have an overhead or otherwise obliquely-shining lamp upon the device. Also noted a couple of expired no-see-ums (midges? who knows!) atop the doorbell... wonder if they are the relics of floating ghosts. Lights & bugs remain the principal suspects.