Hi, I have a HG659b, being a Spark customer, and was able to play varied content with the thanks to Getflix for quite some time, following Getflix's settings etc. 
I lost ability to cast media from other countries to my chromecast a couple of months ago. I ensured all settings were set up as directed on Getflix's chromecast Block Public DNS settings pages. Though the player does connect, like stating 'bbc iplayer ready to cast', with BBC it just loads and loads without playing the video, or with ITV it shows a play error when it comes to playing the video. I reset my chromecast etc, to ensure this was not the problem.

When I ping 8.8.8.8 I do not get Request Timed Out, so I figure that google is not being blocked, correct me if I am wrong here. I have googled to exhaustion, I have contacted Getflix, with a response, keep trying to connect and it will in the end. I would love to see the day, as I tried and tried repeateldy and on different countries and providers. Regardless to what device I use, browser I use, or app, it makes no difference, the problem persists. I can cast NZ content and plex with ease, so it seems to be further afield.

I also am not able to play videos on my ipad from BBC iPlayer, yet can do so through browser on my laptop.

Is there a setting I have missed, or do I need a different router?

Any help is appreciated.