Theme Suggestion for overridding page-title.html.twig file?
You can do this by adding your own suggestion. In your theme's ThemeName.theme file add a hook_theme_suggestions_HOOK_alter() for the page title:

// Add content type suggestions, e.g. page--node--article.html.twig.
function ThemeName_theme_suggestions_page_title_alter(array &amp;$suggestions, array $variables) {
  // Are we looking at a node?
  $node = \Drupal::routeMatch()-&gt;getParameter('node');
  // Object check required, sometimes it's a string, yes, really. Who knew?
  if (!empty($node) &amp;&amp; is_object($node)) {
    array_splice($suggestions, 1, 0, 'page_title__' . $node-&gt;getType());
  }
}


Then create templates per node type, e.g. page-title--article.html.twig, page-title--custom-content-type.html.twig etc.

Edit: rather than the array_splice you can just push suggestions onto the array, e.g.:

  if (!empty($node) &amp;&amp; is_object($node)) {
    $suggestions[] = 'page_title__node';
    $suggestions[] = 'page_title__node_' . $node-&gt;getType();
  }


array_splice() is just a trick I commonly use to position suggestions in the $suggestions array so I can control when they are picked up and used.