Doorbell not functioning
I use a Vivint security system and it exposes the HTTP automation port for both of my doorbell cameras. I've ensured that I've enabled the doorbell functionality in CameraUI and have entered the correct HTTP port for both doorbells.

Whenever I ring the doorbell, however, I get the following error: 
Back Doorbell: {"error":false,"message":"Handling through extern controller.."}

The doorbell notification never comes through on my Homepods. Any help with regard to things to try would be greatly appreciated!