It shows that MiTV is the not culprit as many have been thinking. The TV can play 4K and the HDMI is complying with HDCP 2.2 with HDR working..If the internet downloading speed is not the issue, then it could be only be the DRM certification issue as DRM is at level-3 and not level-1..Just hope Xiaomi can come out and help..
BTW, just want to mention that Google Widevine DRM Level 1 is not equal to Netflix 1080p/4K. It is a prerequisite but not enough. Netflix certification is also needed.
Ref:
https://www.cnx-software.com/2015/1...-tv-box-play-full-hd-or-4k-videos-in-netflix/
Some device running Google Android TV OS, like Starhub Go Streaming Box, Mecool KM8 and the new Mecool KM3, do have Google Widevine DRM Level 1, still they are not certified by Netflix and therefore do not support Netflix HD. There are hacks to support up to 1080p but Netflix is actively blocking these hacks.
https://www.cnx-software.com/2016/1...any-android-device-with-widevine-level-1-drm/
Mi TV Pro in India should fall in the same situation as well since it runs Android TV OS but lacks Netflix certification.
https://beebom.com/xiaomi-mi-tv-pro-lineup-netflix/
Still for these boxes since they all support Chromecast, you can cast from mobile phone to get Netflix.
For China versions of Mi TV or other Android device with only Google Widevine DRM Level 3, you will only get SD480p or 576p and there are hacks like mod Netflix apk to get 720p but again Netflix may block the hacks.
Mi Box S, on the other hand, are fully certified by Google and Netflix, so you can watch 4K HDR Netflix as long as you have a compatible display device like Mi TV (4k, HDR, HDCP) and a good connection with Netflix servers.
The issue with Mi Box S in this particular case is that it may not detecte the TV property.