Endnote 9: Multiple citations problem

Endnote 9 problem: Multiple citations of same author come out differently. Example:

 (Horn, Nolen, & Ward, 2013; Koretsky, Nolen, Gilbuena, Tierney, & Volet, 2014; Nolen, 2007; S. B. Nolen, I. S. Horn, C. J. Ward, & S. A. Childers, 2011).

These are all in my library in exactly the same way, but in the last citation, it decides to put in their initials. Suggestions?