If you don’t have any specific reasons/settings in your Router, for your local lan, i suggest you reset your Router to Default Settings …
You should NOT open any ports to Wan !
And if you have a Camera in a Subnet, it’s obvious this Cameras IP, you should “Allow” into your “ordanary” LAN ( Where your HA is … If that’s how your “setup” looks like
PS: I Wonder why/how you manage to create a subnet !