@donnadee: Please can you try restarting your phone in Safe Mode and monitoring the performance for a few hours. If you no longer receive any pop ups during this time then restart the phone as you would normally and delete any recently installed 3rd party apps, as the issue is likely to be stemming from an external source.
To enter Safe Mode, press and hold the Power button until the 'Power off' prompt appears on the screen then release > Touch and hold Power off until the 'Safe mode' prompt appears then release > To confirm, tap Safe mode > With Safe Mode enabled, ensure Airplane Mode is turned off.
