When exporting your document to LaTeX, only numbered sections will be included. This is closer to LaTeX and different to how other exporters work (see Table of Contents). If you need an unnumbered section to appear in the table of contents, use the property ‘UNNUMBERED’ and set it to ‘toc’:
:PROPERTIES: :UNNUMBERED: toc :END:
If you want the LaTeX exporter to behave like other exporters,
customise the variable org-latex-toc-include-unnumbered and
set it to t:
(setq org-latex-toc-include-unnumbered t)
or add this setting in the local variables.
In this case, unnumbered sections will be included in the table of contents, unless you set the ‘UNNUMBERED’ property to ‘notoc’:
:PROPERTIES: :UNNUMBERED: notoc :END: