Could be a bug, but could also be a template location problem. From version 4.x (not sure from which minor version) all templates in override.ini need to be in override folder, all other should be in templates folder. So check your template location.
the template location it's right because I have developed template search in a ezpublish 4.2 and the override works than I have upgrade to ezpublish 4.4 and the override don't works. So I try my template and override in two anothers ezpublish 4.4 and override don't works, move again to a old ezpublish 4.2 and works.
I think it's a bug because I see that in ezpublish 4.4 there is a new field in table ezsection called "identifier" for section.