Publication Manager doesn't recognize map specialization vocabulary

I have a map specialization that I've added to our configuration. It validates properly in Oxygen, works with the authoring bridge, and validates in the repository. When I attach the map to a publication, it opens, and any content in it displays properly in the preview. However, Publication Manager doesn't recognize the root element as a map specialization. I cannot add any children to the root. If I check out the map and add topicheads, topicrefs, and topicmeta elements, Publication manager recognizes these, but displays the content in my navtitle specializations with the text "undefined." When I check it out, it's exported with a .ditamap extension.

Publishing to our custom PDF plugin fails. The locale folder in the output directory has only the publication .met file and baseline.en-US.xml file. If I publish to SDL LiveContent Reach, it also fails. However, all files are exported correctly. The output fails at the point where the ZIP event should take place.

I have tried adding a template for my specialization to TemplateSpecification.xml, but that doesn't seem to have any impact. Is there some other configuration file I need to modify to get Pub Manager to recognize my specialization vocabulary?