Named destinations missing in PDF

Hi All, Clients are using FrameMaker 16.0.4.1062 with structured documents. I am seeing some cases where cross-references are working in FrameMaker but not in the resulting PDF. When I check the PDF, the link is pointing to a named destination that did not get created; in other words, the named destination is not in the PDF. Has anyone else seen this? So far, I have seen this with two separate clients. Thanks.