This issue is all over the web. No, I do not have a solid fix but have had luck with turning off the firewall in the router and using the DNS 8.8.8.8. Be sure the cloik in the smart TV is set and if this TV has a country or region it is set to where you are.

As I've had prior discussions on the firewall, I no longer write at length about why and why it isn't a big deal.