a KEY point in the attached KB article is
"As an alternate solution, you could make certain that all author names are consistently entered into your EndNote library, including spacing and punctuation. For example, if you have entered
Smith, J
as an author in one record, you need to make sure every other instance of that author’s name in that library is identically formatted. Please note that a difference as small as one space may cause EndNote to believe it is dealing with two separate authors and add the initials."