The Poco F2 Pro has received several MIUI 12 updates since the rollout began weeks ago. It wouldn't be a proper Xiaomi update rollout without a build breaking something, though, and it appears that's exactly what happened with the stable MIUI 12 update for the Poco F2 Pro.
Going by reports on the Mi Forum, the update with build number "MIUI 12.0.1.0" broke HD playback support for Netflix. The Poco F2 Pro typically offers Widevine DRM L1 support, but the stable MIUI 12 update removed that and downgraded the phone's Widevine security level to L3. This means that owners of the Poco F2 Pro currently running the stable MIUI 12 update are unable to play HD streaming content from Netflix and similar platforms.
It's not the first time a major update has done something like this. The Android 10 update for the Redmi Note 8 Pro broke HDR support for the device back in March; it wasn't until June that the issue was fixed. Mi Forum mods have confirmed that the issue has been acknowledged by the dev team, though, so a fix for the Poco F2 Pro should arrive soon.
Source(s)
Mi Forum via AdimorahBlog