Microsoft Word Forcing "Spaces" Switching
Note: This is a blind answer attempt: I don't have Microsoft Office on any of my computers.

Could you try:

System Preferences
    Mission Control


to deactivate:

    ☐ Automatically rearrange Spaces based on most recent use
    ☐ When switching to an application, switch to a space with open
               windows for the application


I deactivated both because they were always disturbing my working environment in a way I wasn't able to go ahead with what I was running in parallel on many spaces.
Since I made this setting I'm able to work with an environment not running under my feet.