Facing similar battery drain issues. Turned off Nerby Share, as well as its notifications. Let's hope it works.I have RN10Pro EEA (Sweet) on latest MIUI ROM.
I have been trying all the suggested solutions with no success for me.
Now I found one that makes a big difference but does not completely fix the problem.
I found that even though "Nearby Share" was tuned off, look further down the screen you see that notifications (on the same page) remains switched on, and the small print says it will continue to scan for nearby devices even though bluetooth etc is turned off !!!!
My RN10P is often kept next to another device ovenight, so I suspect it was scanning even tho it shouldn't.
Anyway, since turning off the notification setting - the cell standby has dropped from 1500 mAh to 230 mAh per 24 hrs, and is no longer top of the list.
I do keep my old Windows Phone near my Xiaomi phone, and I often leave Wi-Fi on on both of them overnight. Do you think it might be causing this issue?