If you don't have Google Keep, install it. Then go into Google Keep > Settings.
https://drive.google.com/file/d/0B0BiOBomwPHTdDNrLUx0MnVEbXc/view?usp=drivesdk
Same problem here. Is everyone on Sprint, or is this a Samsung thing?
mine happens sporadically, and at least once or more per day. It's really annoying!