using m6s  & i noticed that battery drains quickly than expected. only lasts 8hrs even when not heavily used (only some calls and chats no game)

also some apps like instagram, Line and Viber notifications are delayed or will only shows up when the app is running.  (and yes the notification settings are all set even as priority ) i even reinstalled the apps and made sure that they are updated

any suggestions on what to do? downgrade perhaps?
ps i'm new to meizu, Android, and flyme.

thank you