Tabs only work for first variant in Node Page

Yeah, see #2634276: Multiple routes break active trail and possibly other behaviors. Probably a duplicate of that issue.

I am having the same issue

Noting here that creating an additional Page Manager Page with a Panels variant and Node (Content) context assigned with an existing node also causes this issue, even if the same node is viewed at the provided /node/{node} page and displays tabs correctly there.

1. Create a new node
2. Create a variant for Page node/{node}
3. View node at Page node/{node}
4. Create a new Page and provide the node as a context using a new URL
5. Create a new variant and add tabs, menus etc.
6. Node visited at node/{node} still displays tabs, Node visited at the new URL does not

I might get time to debug it later, not sure.

Dirty solution for production site untill they solve the issue of route name

/**
 * Implements hook_menu_local_tasks_alter().
 */
function <MODULE_NAME>_menu_local_tasks_alter(&$data, $route_name) {

  // If route name match node router.
  if (strpos($route_name, 'entity.node.canonical') === 0 && $route_name != 'entity.node.canonical') {
    $manager = Drupal::service('plugin.manager.menu.local_task');
    $data['tabs'][0] = $manager->getLocalTasks('entity.node.canonical')['tabs'];
  }
}

This problem is for all entities not only for 'node', I like the solution and would enhance it this way:

/**
 * Implements hook_menu_local_tasks_alter().
 */
function <MODULE_NAME>_menu_local_tasks_alter(&$data, $route_name) {
  $all_entity_types = \Drupal::getContainer()->get('entity.manager')->getDefinitions();
  foreach($all_entity_types as $entity_machine_name => $entity) {
    if (strpos($route_name, 'entity.'. $entity_machine_name. '.canonical') === 0 && $route_name != 'entity.'. $entity_machine_name. '.canonical') {
      $manager = Drupal::service('plugin.manager.menu.local_task');
      $data['tabs'][0] = $manager->getLocalTasks('entity.'. $entity_machine_name. '.canonical')['tabs'];
    }
  }
}

Thanks to Alexei Gorobets for consulting.

#6 worked great for me. Thanks, gang!

#6 worked great for me too.

Last patch from ( #19 ) https://www.drupal.org/node/2634276 fixed my tabs.

#2634276: Multiple routes break active trail and possibly other behaviors