Screen issue !! tabs s 10.5. sprint topic

So it's been about 2 months since I got my tab s 10.5 and is the sprint variety . The issue I'm having is that randomly throughout the day I'm using the tablets and the screen gets completely unresponsive . Touches won't work the soft keys don't work . The only thing that works is the home button ,the power button and the volume up/down . I can fix it by locking it and unlocking the screen and then everything works again but as you use it the same things happens and you have to lock/unlock to fix it . I've already tried to factory reset it but it doesn't help . I don't know if is software or hardware issue since is fixed by locking/unlocking the screen. Any help would be greatly appreciate it.