Thanks for being with Samsung and for sharing your concern. Let me recommend some steps to further isolate and determine what you are experiencing. Please be aware that device speeds may vary based on multiple outside factors. It appears that there may be a third party app or other program that may be leading to what you are experiencing. Placing your device in safe mode disables all third party apps upon startup, to help determine if the use of a third party app is interfering with your device .restart your phone in safe mode. While your phone is powered off, press the power button to turn on the phone, once you see the Samsung logo appear press the volume down key and hold it until you have completely booted up. You will see the words "Safe Mode" displayed in the corner of your screen if done correctly.