If you don’t wish to have author name initials to be displayed, check the Name Format* (see attached image) setting of the APA 6th to see that the “Initials” setting is set to: Last Name Only.
Note that any changes to the APA 6th output style file will be saved as a copy (i.e., APA 6th Copy) so you will need to change your EndNote and MS Word settings to use the APA 6th Copy.
____________
*Go to the EndNote toolbar, select EDIT, OUTPUT STYLES, EDIT APA 6TH. The APA 6th output style window will be displayed onscreen.
Then you gotta either edit the two citations so they are both the same with respect to the first author (preferred) as Endnote thinks they are different - or edit the style so that it (in cases where there were two authors with the same surname) incorrectly doesn’t indicate that fact. That setting is a tick box (edit output style) under citations, Author Name “Use initials only for primary authors with the same name” - unselecting this should get rid of the initials, but that might be the wrong thing to do if they really are different authors or if other refs are say R. Smith and G. Smith and should be distinguished.