I am using MAC.
I am trying the default zoom display of Acrobat. I went to Preferences --> Page Display --> Zoom and selected my desired zoom. I saved the document but nothing happened. I restarted the program - still nothing. I have restarted the computer - more of the same nothing.
I spent some time reading about this online, nothing helped.
Changing the preferences will not change the settings in the document.
Open your file, go to File - Properties - Initial View and change it there.