hyphenation randomly not occurring (InDesignServer 2014)

Running IndesignServer 2014. Hyphenation on paragraphs not occurring throughout a given result InDesign document although the hyphenation property is set true. The same input (xml) with different results: one pass has no hyphenation; a different pass has hyphenation from the same script, the same starting template, same paragraph styles, etc. (Using Adobe Paragraph Composer.) WIthin the same document, all hyphenation is either not occurring at all in the document or else occurs normally throughout the document. When opening the resulting document in a desktop version of InDesign, hyphenation is true even though no hyphenation occurs. If in the desktop version I change from Paragraph Composer to Line Composer and then back to Paragraph Composer, hyphenation appears.  Any ideas?