Hi,
So I have recently started experiencing problems casting Udemy to my Living room Sony TV. Weirdly it worked just fine with standard google chromecast connected to my bedroom TV (Samsung). That pointed everything to issue being somewhere in Sony so I have started digging through options. The only thing that helped was uninstalling updates to google chromecast. Now works great. Can you fix it or inform google that they broke it so it's not annoying people anymore please. Cheers!
