Make sure that you're exporting your content with the most recent version of in5, version 3.8.7.
It's likely that there is something covering the links. If something such as an invisible button (shape with no stroke and no fill) covers a link or if a group containing objects that don't individually cover the link but form a rectangle that does, then the links won't be clickable. I'd recommend checking that there isn't anything covering the links.
If you're still having issues after updating to the latest version and checking that nothing is covering the links, would you be able to send us page 7 of your InDesign file (or a sample file that recreates the issue)? Sending via WeTransfer.com or Dropbox Transfer works well.