🇪🇸Spain @patricia.gende

But this does not work on all sites. In my case that I have a multisite, it works in the site that I have comments but not in the rest.

The problem is in the dynamic_page_cache module of the core. It is necessary to replace the following line:

use Drupal\Core\Cache\VariationCacheInterface;

with this one:

use Drupal\variationcache\Cache\VariationCacheInterface;

The tab exists between Edit and Delete, but it has no text and is therefore not visible to the simple eye. But if it is created, if you look at it, it creates a small space between the two tabs.