This sounds as thought the there is one of two issues. On there could be malware on the device or OS didnt seat well with the device. I suggest downloading and running the safe security 360 app. Run the malware and cleaning to remove unwanted files and malware. Then back up your data and factory reset your device. This will fix your device 90% of the time. If this issue still persist the you will need to contact samsung for service because it might be a device issue.
... View more