Thank you for reaching out. Do you experience these symptoms if you test your device in safe mode? If your phone is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe Mode feature. In Safe Mode, your phone won't run any third-party apps. This allows you to easily identify and remove the app that may be causing the problem.
Some app has a permission to adjust system settings.. I wonder if a third party app is involved. Long press the power button and the boot options will show, than long press power off option (a fly out will appear saying safe mode) than tap the safe mode icon. Your device will reboot into safe mode disabling third party apps. If the symptoms disappear, than you'll know it was I third party app with too many permissions causing it.