Created attachment 166979 [details]
Just an example of badly ordered headings.
Headings are used by the readers and converters for making a content tree and navigation, it's important to keep them ordered.
Ivan Stefanenko committed a patch related to this issue.
It has been pushed to "master":
tdf#137968 Added check for the headings order
It will be available in 7.1.0.
The patch should be included in the daily builds available at
https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.