Windows 10 - Users already logged in at boot

Open Settings, Accounts, Sign-in Options.

Disable Use my sign-in info to automatically finish setting up my device after an update or restart

Hope that helps. Let's know.

You may also need to change the settings that turn shutting off into hibernate. Windows 10 will go to hibernation instead of shutdown even if you disabled it and asked to shutdown.

The setting to disable this is reached like this:

Go to Windows 10 Configuration Panel.
Go to the System panel.
Go to Alimentation panel in the left list.
Click on Suplementary Alimentation link on the right.
Click on Choose Action of Power Button link in the left list.
Click on Modify Currently Unavailable Parameters if your not Admin.
Click on Activate Fast Boot to disable it.