I record the video via RTSP in Blue Iris, and the BI timeline shows all the dropouts:
I doubt it's the WiFi connection, because the new wireless access point is now only about 30' away, through wooden walls, and the Amcrest Smart Home app shows "WiFi signal strength: Good" any time I can talk to it:

If I bring my phone or laptop out to where the doorbell is installed, I get good or excellent WiFi connection to the same SSID.
Is there any way to get a log from the device to see why it's disconnecting or rebooting or ???
If I point a browser to its IP address, I get a blank page with a title of "WEB SERVICE" but no visible content. The page Source shows some stuff, but nothing displays. I've tried Safari, Chrome, FF, and Edge, and none of them displays anything other than a title bar with "WEB SERVICE"