Why does Insert TOC ignore h1 headings?

Hi, I have been using libreOffice Version: 6.0.5.2 (x64) on Windows 7 for about 6 months.

I having been inserting TOCs into documents using Headings 1 to 4, without any problems.

Recently it has been ignoring Hi headings and only using Headings 2 to 4, so my TOC is missing lines.

Say I go One (set to Heading 1) Two (set to Heading 2) Three (set to Heading 3) One (set to Heading 1) Two (set to Heading 2) Three (set to Heading 3)

the two lines containg One are not in the TOC.

I’m baffled.

I have altered the document by changing the page size.

Try Tools> Chapter numbering - make sure that level 1 is linked to Heading 1. If that doesn’t fix it, check the settings in the TOC window.

Brilliant, linking level 1 to heading 1 worked!