Internet Service Provider?
Can you please try it again with the settings below?
Internet Connection: Auto Configuration
DNS Type: Obtaina DNS server address
Enable DHCP-PD: Enabled
Enable Automatic IPv6 Assignment: Enabled
Enable Automatic DCHP-PD in LAN: Enabled
Auto configuration Type: SLAAC+Stateless DHCP
My router does not receive DNS IPv6 but my computer does and my internet on IPv6 works fine. 
Try testing you IPv6 with this site: http://ipv6-test.com/
I am using the default settings.  I use an arris  SB6190.  IPV6 works fine with my google wifi router as well an my Netgear R8000p, just does not work with covr.