[jem]

No hang on, it’s not completely clear what the situation is here.

Tell me if I have this right.

You have a device running a service which responds on port 16565. Internally it is on an IP address of, say, 192.168.0.100, and if from within your internal network, if you browse to that address and port it works, yes?

Now you have set up port forwarding to it from your public address of, say, a.b.c.d, and from somewhere outside your house, if you browse to a.b.c.d:16565 it also works?

Have I got it right up to now?

But, if you browse to a.b.c.d:16565 from within your house it doesn’t work? Again is that right?

If all the answers to the above are yes; then it is exactly as ‘gunner45’ says; it’s due to the lack of support for NAT loopback in the Hub 5 and there is absolutely nothing you can do about it.

If so, as Paul says, stop complicating the situation.