Same here, my battery at standby is now only 18hrs 30 mins which was 1d 2 hrs before the one ui 2.1 update, and my battery backup is reducing day by day now it's only 15hrs 20 min.

Same with me bro,my m31 is showing 18hr 30 mins on full charge.My battery was working pretty good but after one ui 2.1 update, its weird but when my phone is fully charged its weight remain the same 190g, but when it discharges its weight reduced to ...