It's not your router per se. It may be the DNS server you are using or a problem with your browser. Site works fine for me after having to look up the link (spelling mistake and all) because you did...

I guess they aren't really interested in engaging with their cutsomers or the community. TP-Link customer service attitude/approach hasn't really changed it seems.

Your router may allow you to define the same ssid to 2.4 and 5g networks, but doing so is not good procedure and can result in devices that support both protocols having difficulty connecting.

Your router may not be able to connect to the defined dns server.

Perhaps you could take a moment and introduce yourselves. It is only recently that users identified as representing Tp-Link have begun participating in their own forum. Are you employees of Tp-Link...

Any differences in firmware between US and Canadian versions is to comply with regulatory differences and either firmware will work in a V1 C9.