Not working on Sublevel menus

Ok, thanks for bug report. I'll investigate it and let you know.

@ThirstySix - thank you for fix proposal. Could you please re-submit it as proper patch please?

In general, I understand approach here, but I think that it can be improved by using recursive approach, instead of making duplicate code in one method.

I did a bit of refactoring, also integrating the fix in https://www.drupal.org/project/translatable_menu_link_uri/issues/2932662. Surely it could be better, but at least it uses recursion.

/**
 * Implements hook_preprocess().
 */
function translatable_menu_link_uri_preprocess(&$variables, $hook) {
  // Let's apply this on menu theme (menu block).
  if ($hook == 'menu' || preg_match('%^menu__%', $hook)) {
    foreach ($variables['items'] as &$item) {
      translatable_menu_link_uri_iterate_menu($item);
    }
  }
}

/**
 * Iterate over the menu and check for sublevel menu links
 */
function translatable_menu_link_uri_iterate_menu(&$item) {
  if(($item['below'])){
    foreach ($item['below'] as $key => $value) {
      translatable_menu_link_uri_iterate_menu($item['below'][$key]);
    }
  }
  /** @var \Drupal\Core\Menu\MenuLinkInterface $link */
  $link = $item['original_link'];
  $plugin_id = $link->getPluginId();
  $url = NULL;
  // If menu link is generated by menu_link_content, let's go deeper into details.
  if (strpos($plugin_id, 'menu_link_content') !== FALSE) {
    $link_entity = \Drupal::service('entity.repository')
      ->loadEntityByUuid('menu_link_content', $link->getDerivativeId());

    // We have entity, now, let's translate it.
    $translated_entity = \Drupal::service('entity.repository')->getTranslationFromContext($link_entity);

    // We inherit options from current (overriden) element.
    $options = $item['url']->getOptions();

    /** @var Drupal\link\Plugin\Field\FieldType\Linkitem $url */
    $url = $translated_entity->link_override->first();
    $item['url'] = $url->isEmpty() ? $item['url'] : $url->getUrl();
    $item['url']->setOptions($options);
  }
}

@sanci - thanks. Could you please post change in form of patch?

I implemented the patch but my site stopped working and I got the following error in the Recent Log Messages
TypeError: Argument 1 passed to Drupal\Core\Entity\EntityRepository::getTranslationFromContext() must implement interface Drupal\Core\Entity\EntityInterface, null given, called in /srv/bindings/0e54cc032c4140da8242a55169a483bd/code/modules/translatable_menu_link_uri/translatable_menu_link_uri.module on line 111 in Drupal\Core\Entity\EntityRepository->getTranslationFromContext() (line 82 of /srv/bindings/0e54cc032c4140da8242a55169a483bd/code/core/lib/Drupal/Core/Entity/EntityRepository.php)

Please help I need this to work with the sub menus too

The patch in #11 works for me and does not result in any errors in the watchdog log.

Can't reproduce. Works for me!

Link override wasn't working for sublevel menus on my case too. Then by applying the patch in https://www.drupal.org/project/translatable_menu_link_uri/issues/2925482... it started working without messages on log.

I see that patch doesn't apply, as there were few smaller changes. I'll do a rebase of patch, and introduce few small refactorization fixes (phpcbf).

Thank you for all your input, fix proposal and patch provided. As mentioned above, I slightly updated patch (made phpcs / phpmd happy) and commited it.