sergiosp Hi,
The similar issue persists also with default Joomla template assigned. Ref: Screenshot henceforth, it appears to be core Joomla file missing/being corrupt issue wherein menu type like "Single article" is appearing fine as envisaged
You may try to reinstall Joomla core files by the steps as outlined in admin panel ---
Component > Joomla Update > Live Update > Check for updates > Reinstall Joomla core files (click)
Would suggest to take backup of your site before performing aforesaid steps, in case rollback required whilst facing any issues e.t.c
Also, Kindly confirm if the issue persisted with older version of Joomla