Metadata displayed on the page

hello! so my metadata are displayed on the page instead of creating the tags and attributing values to them

title: Plombier paris

displays on the content of my page :
title: plombier paris

This doesn't ocur on all the pages even though i used the same code in all of them

Might be because the page header is not well formatted.

Make sure no spaces are on top, and the page starts with ---. Try comparing with pages that work fine.