Page properties report: Sort by doesn't seem to work.

With a report against a modified product requirements template, sorting by a specified column seems to not work. Column is named "Associated Releases" (no quotes), and the contents of that column are one or more links to other confluence pages, or plain text of a similar format (i.e. "Product 1.1", "Product 1.2", "Product 1.3

Product 1.4", where Product 1.1 is plain text. Manually sorting the columns seems to work fine.