When I look at your Heading 1 style, I see a dot leader in the second tab stop.
The "10" moves past your first tab stop. It looks like your style is based on a TOC style.
00 deleteme 3.png

00 deleteme 4.png

00 deleteme 1.png

Changing the first tab stop to .5 seems to cure this problem.
00 deleteme 5.png

00 deleteme 2.png


The numbering inserts a tab after the number to separate the text from the number.

Note, you have this style set to automatically update based on formatting. This is generally a bad idea.
(I got the dot leader to appear at the end of entries that did fit by pressing the tab key at the end of the heading, just to show you that it is there in all of your headings, not just the ones that were giving you problems.)

Working with Tabs