melville and its child theme

According to the codex your file needs to be called childtheme/loop-home-page.php if you did just then <?php get_template_part('loop' ,'home-page') ?>you would call it loop.php not sure if that helps at all.

Another thing is make sure your page is using your custom template file as this could also be your problem. What is the name of your custom page file? if it’s home.php this may be the problem.