Last TOC entry hidden in overset text
I have what to me is a bizarre problem. I have created a document and added a Table of Contents. Everything has worked fine - all the TOC entries (3 levels) appear and are formatted correctly until I add a final text box with a top level format (Heading 1). When I update the TOC, this final entry disappears into the overset text.

The final spread looks like this:

but the last entry ('Acknowledgements') doesn't appear in the TOC or at least it's hidden in the overset text. I cannot get the last Heading 1 text entry to appear in the TOC. If I demote it to Heading 2 then it appears correctly under the previous entry:

I have simplified things as much as possible to isolate the problem, removing any 'Keep' options for the TOC entries and removing any surrounding text. It seems no use to create dummy text boxes and try to follow the overset text - it never appears.
I am stumped. Am I missing something obvious? Can anyone shed any light on what's happening and why I cannot get this last entry into the TOC?
Thanks, Stephen
