I'm trying to resolve a port forwarding issues in regards to how my router is dealing with Destiny.

At the moment the PS4 network test is coming back as Nat2 (moderate), but loading up Destiny comes up as Nat3 (strict) meaning no in game comms.

 

Currently we are using a TG582n supplied by telecom/spark and there are directions for which ports to open within the router, which i think I'm doing correctly.

Destiny Port Range Direction
7500-17899 (TCP) Outbound
30000-40399 (TCP) Outbound
3074 (UDP) Inbound and Outbound

The issue is when i go to apply the specific config, i get an error:
"Error: The port configuration of the game or application conflicts with an already assigned game & application. Assigning this game or application is not possible."

Ill try to embed screen cap (censored) to help illustrate.

Is there something obvious I'm missing? Is there another way to fix the port issue (learn telnet - shudder) or do I need to consider upgrading the router (if that will resolve the issue).

Screen Caps
Initial screen
https://imgur.com/wsFUv8i
Game or Application Definition
https://imgur.com/CneFewh
Application
https://imgur.com/LiFuXaU
Error
https://imgur.com/G2v7kIc