Please follow below steps for troubleshooting ：
1. Access to Safe Mode ( long press power key → Tap and hold " Power Off "→ Tap" Ok " ) ： If your phone / tablet works well in safe mode , malfunction might be caused by 3rd party apps. Please reboot your phone / tablet and check again if it works well.
2. Clear App Cache : Tap " Setting " > " Apps " , Find the abnormal application that you want to clear up > " Clear cache "
3. Update the app：In Play Store, Tap a menu icon on the upper left corner > " My apps&games " >" UPDATE ALL "
4. Check for firmware updates：In " Settings " -> " About " -> " System update " > Tap " Check Update "
5. Backup your data and perform factory data reset. Note: Once RESET was performed, all data, apps, settings and personal information will be deleted after initialization.
If above steps can't solve your issue, please contact ASUS Customer Center for help.