From TP-Link FAQ which may help. Not sure if it is supported for your router. Hope it helps. https://www.tp-link.com/us/faq-273.html

Not sure if your address is a typo or not. It should be 192.168.0.1 if you are using the default LAN IP address. Also try power down the router and back up to see if that helps.

I have a C7 which is different. I had to play around with different settings a bit to get IPv6 to work with Comcast. The steps I used are: IPv6 [*]Turn on [*]Connection type Dynamic IP (SLAAC/DHCPv6)...

After a factory reset, you need to use the default user-id and password. If that is what you are using, try a factory reset again and also try power off, wait 60 sec, and power on.

Not sure what you are connecting. On my DVR when I use the DNS, I use the server port not the HTTP port. So it may be the port number you are using. Example: Alias dvr Register mode IP/Domain Address...

Or you can do a hard/reset and re-enter your config info.