New level does not appear in TOC

I have just added a new heading level (3) to a document. I have successfully created a new paragraph style (using Styles > Modify) and chapter number (using Tools > Chapter Numbering).

The chapter number and paragraph heading appear in the body of the document but NOT in the Table of Contents.

I have tried making changes in Insert > Table of Contents but whatever selections I make in the dialog (Levels and Paragraph Styles) seems to have no effect on the Preview or in my document.
The TOC only shows levels 1 and 2.

I assume you have left Evaluate up to level at the default of 10, if you had changed to 2, then after changing it up to 3 then you still need to update the index. Right-click on the TOC and select Update Index. Cheers, Al

Right-click on TOC and Update Index anyway. You need to do that, it doesn’t update by itself. I have icon on Toolbar to do that and it makes a handy shortcut so I can check that I’m using my heading levels correctly.

To @EarnestAl.
Thanks for your response. The TOC now works.