Hi! Again, I apologize for writing bad English.
Put into context my problem: when you install Display Suite, the Select Layout option appears in Manage Display within each type of content created. When selecting a layout we can have control over where and how to display the title field.
This worked fine until I installed a module called: Field Group. After installing this module, I have experienced two problems with Display Suite. One is as follows:
I set my_content_type to show the title field in full-content view. But it never appears in the frontend.
I deleted the Drupal cache. I cleaned the Drupal database with Optimize DB. I uninstalled the Field Group module. Nothing works.
Any idea how to fix this?