I think this is also stopping NETFLIX working in 4K for me.
I have managed to get NETFLIX to work in 4K in EDGE and Windows App but it had stopped working in 4K.
I did a system restore which was dated 2nd Sep 2018 and it all burst into life. I was suspecting a windows update but I am thinking it is something else.
It is now broken once again. The only apps that changed since the system restore is AVAST updated itself and I reinstalled Chrome.
Also I launched SKY Sports Player which has CISCO VideoGuard protecting the video.... VIDEO GUARD stops working as soon as it detects apps that can take pictures (Paint, Snippet etc). I am about to watch SPAIN v ENGLAND using SKY Sports Player so maybe I will uninstall Cisco VideoGuard later. I will post updates.
I was wondering if anyone else reported issues with Cisco VideoGuard (version 9.0.1.4396)