Hi SlickRCBD, I am Paulo, an Independent Advisor willing to help.
The shutdown in Windows 10 is not a full shutdown but hybrid shutdown that is turned on by default. It is also known as the FastStartup which helps your PC boot up faster after shutting down. This feature was first introduced in Windows 8. The shutdown command that you're using is just a normal shutdown wherein it closes all and gives you a completely new Windows state.
If you want the hybrid shutdown command, you can enter Shutdown /s /hybrid
For the list of other commands
https://www.howtogeek.com/512012/how-to-shut-do...
If you want to know more about the hybrid shutdown, you can check this article
https://www.howtogeek.com/349114/shutting-down-...
If you want to turn off the Fast Startup feature
https://www.tenforums.com/tutorials/4189-turn-o...
(Disclaimer: These are non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.)
Let me know if this helps.