Try deselecting the pen/write tool in the top right corner of your screen. GoodNotes or Notability doesn’t allow you to click links when the pen is selected. If you deselect the pen/write tool, it allows you to freely click on links. When you're ready to write again, you click the pen tool again.
It that doesn't work, please re-setup your planner. Delete/Remove the old files from your device and app, download again the pdf planner by using Safari browser (not Chrome) and import again into your app.
If the issue persists, please email: info@my-digitalplanner.com