same issue with k20 pro, the process SECURITY app is draining my battery but just 15% in 8 hrs, i installed betterbattery stats, wakelockdetector but doesnt work very well on miui....
I'm using a old version with 1080p support 4.16.3 and works fine.
I have 2 issues
1.- the search app crashes the miui launcher
2.- All the notification are displayed on AOD (i prefer a way to filter the notification on AOD)
Sent from my Mi 9T Pro