Hi
Many thanks and I think you have caused the issue with port forward to PC, therefore any requests are routed to PC and not ps4
You would be better just to open port 80, 443 at firewall only and set UPnP on at router, leave port forwarding unless you are running a dedicated device, such as hosting server etc, which I don't think you are and allow the router to correctly control and look after request made in/out
If you do this, the way it works is the router should keep track of requesting internal IP address out, which allows request back to same internal IP address. UPnP allows a device which has UPnP on, to open as needed.
We have Xbox and play gta5, no issues but we are setup as above, no port forwarding and no ports open, reliant purely on UPnP.
I hope that makes sense and the only real downside is the latency, which is around 22ms, but could lower it if we switched username as suggested and proved works to lower latency, but it stops our full external IP addresses, so we cannot do that sorry.
Many thanks
John