Venu 2 Plus Battery Drain issue

I have found that my Venu 2 Plus that was giving me a battery life of 7-8 days with daily activity of almost 40 minutes is now hardly giving me 3-4 days of battery life.

This has started after i updated to latest Firmware, 15.20.

Another issue i have noticed is with the Bluetooth connectivity with phone. The watch keeps on disconnecting from the phone every now and then, while both of it is well within the Bluetooth range.

Please fix the issue.