H1 tag not showing on front page
go to:
/admin/config/content/ckeditor/edit/Advanced (for Filter HTML)
/admin/config/content/ckeditor/edit/Full (for Full HTML)
Then under Advanced Content Filter, select disabled.

If the above does not do it, depending on which one you are using (filter or custom) You need to go to
/admin/config/content/formats/filtered_html
add the &lt;h1&gt; to the limit allowed html list