Been having a weird issue with Netflix.... I used to be able to see that something was in 4K before I chose it. It used to Say '4K Ultra HD' in the top right corner next to the rating and length of the show/movie. I also used to have a category for 4K content that has now disappeared. Now all of my options just say 'HD', even if I know it's in 4K. Is this because of an update or am I not getting things in 4K on netflix anymore? Any help with this would be great.
Install the "DRM info" app on the shield (from Play store). Run it and see what the Widevine DRM level is at. It needs to report 2.2 for UHD in Netflix. If not, change HDMI cable, shield resolution settings, try another HDMI port on TV, and check Netflix account type hasn't changed.