This makes no sense. I have some reolinks and a Ubiquiti Dream Machine router. I am trying to block the internet on to make them only accessible via local network and VPN. I go to uniquiti / settings / application firewall / traffic rules, and there I choose “block”, then “internet” in “category”, and select my cameras. This makes them inaccessible from the internet, but accessible via local network. Great. But then, if I connect to my cellphone’s internet and turn on the wiregaurd VPN connection to my UDM, the connection works (I can use internet), but the cameras are not accessible. What is going on?
Check your routing. You probably forgot to push the routes of your security camera subnet to your client config.