Writer Table of Contents - doesn't generate anything

[Zoomiest]

Version: 7.5.4.1 (X86_64) / LibreOffice Community
Build ID: 50(Build:1)
CPU threads: 8; OS: Linux 5.14; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US

I am using the above version, of Writer, and it won’t generate a table of contents, despite my best efforts, to tag headings, and then Insert > Table of Contents.

I have read about others who are having trouble. Has anyone found a solution?

[mariosv]

Please attach a sample file, editing your question.