Changes to the way "Shut down" works
When you "Shut down" your Windows 10 machine, Windows doesn't shut down completely; instead, it hibernates. It closes your programs and saves its state so it will boot faster the next time you start the computer.
If you experience problems and need to clear them up, you will need to restart your computer in order for the computer to fully shut down. For more information on this feature click here.
For more information on why rebooting Windows can fix a lot of problems? Click here.