How to update a menu link created with MenuLinkContent::create()?
If you remember the id after saving the menu link

$id = $home_new-&gt;id();


You can load it directly:

$link = MenuLinkContent::load($id);


If you don't know the id, you can load the menu link by a property:

$links = \Drupal::entityTypeManager()-&gt;getStorage('menu_link_content')
  -&gt;loadByProperties(['title' =&gt; 'Home']);

if ($link = reset($links)) {
  // found a link with title "Home"
}