Does the old Hikvision app notify you when someone presses the doorbell and allow two way communication when someone rings the doorbell while the internet connection to the cloud is blocked at the firewall?Here I updated the firmware on my original Nelly DB when it was first posted here on the forum. I put this update in my signature. Many of the users here have done this.
Baby steps when you do this. I have used the Hikvision Batch Configuration program. I no longer use the provided cloud apps (none of them) and VPN to my home network and run old Hikvision app with a direct connect to see all of my motion / doorbell events and live video.
I use the JPG capture mode for my Leviton OmniTouch screens, RTSP or ONVIF for my Zoneminder stuff. RTSP local for my Alexa display (uses a reverse proxy), ONVIF to MQTT for my Home Assistant stuff, RTSP for display on my Home Assistant screens.
The current EZVIZ app has a LAN view function to directly connect to my DB1 via the LAN, but it appears to only allow you to watch the live feed and take a snapshot or video.