Download app called TEST DPC , it resets it completely. Restarts and ask if you want to be device owner. It works, I just unlocked my samsung j7 with that app. How to download it to your device is turn on accessabilty moood, go to settings under talk back settings then go to android setting up switch, it will show youtube, then go to settings in youtube. Go to privacy for youtube. It will take you to internet. Then just type in test dpc. Download the app. Open and set up.