Getting error message "Accessory Already Added" when trying to add my smart video doorbell

I'ave reset my Smart Video door bell & removed my Apple Home app, and re-stalled the app, and still I'm getting the error message 'Accessory Already Added. to add this accessory to your home, you'll need to reset it first. I have reset door bell and Home app. Can any help me. I would have though Apple would have this error message of their home page, to help those who are getting this error message.

[Re-Titled by Moderator]