• This is likely caused by apps that are installed.
• Due to device hardware issue.
• Battery very rarely caused this issue.
Troubleshooting:
Restart your XP6, check whether the issue has been resolved.
If this issue still persists, try to boot your device in Safe mode by following below steps.
Press and hold power key until Power off mode comes on your screen. Press and hold "Power off" for 2 seconds, until Reboot to Safe Mode appears on your screen and Tap Ok.
Device now boot in Safe mode without any third party applications, check whether issue is resolved.
If the issue is resolved, reboot the device from Safe Mode to Normal mode by restarting the device.
Uninstall any recently installed applications and check whether this issue is resolved.