Port forwarding not working on RT-AC5300

[SOLDIERSecondRateRaven]

Sorry no idea. Probably interference, try different channels and make sure the bandwidth is set to 20 MHz.

I have tried a number of combinations of frequencies and channels without change unfortunately. Thank you for all your help though, I appreciate it.

 

[raven-au]

EDIT: I didn't add that one manually either, so I'm not really sure why it's in the list. Perhaps its an Adaptive QoS feature? I also added a port forwarding rule for my Playstation 4, and navigated to canyouseeme.org on its browser, and that shows as locked as well. That seems to at least say that the issue is not specific to the PC.

You have UPnP enabled and Plex is adding its port forward for external clients automatically.
You can disable that in the Plex server config if you wish and you can disable UPnP on the router too if it worries you.

I'd consider using a different port range for Deluge, those ports are the default and I have seen them blocked by some trackers (possibly ISPs as well) but might not be a problem with public trackers, a thought though.

Another oddity you might see is, in my case, Plex has started saying the server isn't available from outside the network showing a cross next to the "Remote Access" when in fact it is reachable. I guess it depends on which firmware and which router you use but its been doing that for me for a while on various firmwares and ASUS routers.