Shutdown Windows 10 truly for a dual booting system

Solution 1:

Have you tried to disable the Fast Startup function? Here is a good article that describes what it does, along with the potential drawbacks:

The Pros and Cons of Windows 10’s “Fast Startup” Mode

That being said, Fast Startup is on by default and disabling it will probably alleviate your problem:

1. Press + X

2. Select Power Options

   

3. Select Additional power settings on the right

   

4. Select Choose what the power buttons do on the upper-left

   

5. Select Change settings that are currently unavailable

   

6. Scroll to the bottom of the window and uncheck the box associated with Turn on fast startup

   

7. Click the button to Save changes

8. Reboot your system

(Source)