"book with link" to topic in subfolder

Hi folks,

I have a book with a link that links to a subtopic (see structure below). When I click Book1, the 1.1. Book doesn't open and won't open when clicked on. I have a vague memory of there being an issue around this but could not find anything in the forum search.

Anyone have any ideas?

Thanks,

Donal

• 1. Book w Link
  • 1.1 Book
    • Topic Linked to
  • 1.2 Book
  • 1.3 Book