@AshK47 Try entering these DNSs here:

@Phildec Yes, that would be a problem since these are different subnets. Change the RE550 IP address to 192.168.1.254 and make sure that its DHCP server is set to Auto or OFF.

@Mercy23_KN Here's the guide for resetting router management password.

@Patrick33 If you're using Windows OS make sure that the new network adapter connection is of a type Private Network.

@elijamiesont Your issue comes from the fact that you're behind a CG-NAT. The only thing you can do is to contact your ISP and ask for an option to have your public IP address on your router's WAN...

@Phildec Use a web browser on a laptop for configuring RE550. The default IP address of the RE is 192.168.0.254. If your router LAN is in another subnet use the http://tplinkrepeater.net while...