niksavinashI resolved by uninstalling Facebook and Messenger 3 days ago. I reinstalled them only today and I'm still fine so maybe they have updated the apps.
With all above mentioned issue I also want to add a most important issue which is battery.. Battery back up is now cut down to almost half even on stand by mode battery drain like screen is on. When I was on a9 my battery is left with 40-50% battery which is now only left with 15-17 percent with the same usage and actually with less usage