On my smart hub 2 I have a port forwarding rule allowing ports 37777-37778 to connect in and out.
Shows in port forwarding page as
Rule name/ mac address of device/external start 37777/external end 37778/ internal start 37777/internal end 37778/ protocol TCP.UDP.
Upnp all off in config page.
My CCTV works with this setup but will not if I delete the port forwarding.
Ports may vary depending on device but best test is to just turn firewall off for a short time and then try to access CCTV.
Hope you get it working.