I have a rooted Samsung Galaxy Tab 3 8.0, it has been rooted for about 5 years but this problem is recent. I have it set to sleep at 10 minutes of non-use but instead of sleeping the screen briefly turns brighter, then locks up & all apps were closed as if it had been restarted. I can unlock it again & open my apps back no problem, but after it does that I cannot lock the screen again. The power button won't sleep it & apps to close the screen only put it back into lock mode but the screen stays on for good. The only way to fix this is for me to hold the power button to restart it. This is really annoying as I usually use my tab for reading. Has anyone else experienced this? Has anyone found a solution? Thanks!