Formatting puzzle

What would cause one document to produce this in the fns:

Quintilian, The Orator’s Education, trans., 5 vols. (Cambridge, MA: Harvard University Press, 2001) 

And another, using identical settings, to produce this (correctly)?

The Oriator’s Education, trans. D. A. Russell, 5 vols. (Cambridge: Harvard University Press, 2001)

The Translator’s name is getting elided in the first document. very puzzling.

what is the output style?  Is the first or a subsequent use of the same citation in one vs the other?