Why remote admin using Port Address Translation - PAT is disabled ?
After get http/1.1 the session is terminated from Hubitat Elevation with unsolicited FIN, ACK .
I want to access my device without subscribing to your remote-admin service, it is malicious to close it to make extra money on our expense.
That's not the reason, a while back people were incorrectly and dangerously exposing their hub to the internet, there were a number that could be found and controlled. That method has been blocked for that reason, if you know what your doing and are able to do it in a safe method it can be done.
You can also use a VPN which is also a safe method.
Port redirect will never be open again, and it never should. It is a huge security risk. As said, you can set up a free vpn to connect to hubitat negating the need to subscribe to Remote admin service.