Go to settings >> system >> About device.
Find "Build number" and click 6 times fast on it.
You will then get the message saying: "You are now a developer"
Come back to Home Screen, and then go back to Settings >> system >> Now you will see the "Developer Options"
Now go to Developer options >> Drawing Section or Rendering Section >> Find "Turn off hardware overlays" or "disable hardware overlays" >> This will force the phone to always use GPU for screen adjustments.