Cannot Access Router Login

No, it’s the WAN port that the router talks to the internet.

To the “GL-MT300N-V2-???” SSID, then it should have a 192.168.8.x IP address. Unless you also have an ethernet connection to the BT hub, in which case disconnect it. Your PC should only have a connection to the router.

The sequence should be:

internet <—> BT Hub <—> Router <—> PC

Cheers.