Hi try this: If not done already update your phone to latest software version which is .47 If you are still stuck, hold power button for 5-10 seconds for force restart Can you tell me how frequent is this issue? Also, what temperature it reaches before you face the above?
Something similar happens to me to. The screen freezes for like less than half a second randomly either while playing games or removing apps from recent apps and while watching videos on youtube. It's really annoying this stutter makes my fps in pubg go from 60 to 29 or 45 fps for a moment