Group clone limit

Hi, I've a group with clone=> true inside a group with colne=> true like this:

          array(
                'id'    => 'menu',
                'type'  => 'group',
                'clone' => true,
                'sort_clone' => true,
                'fields' => array(....)
....
    array('name' => __( 'name',),
           'id' => 'list',
            'type'=> 'group',
             'clone' => true,
              'sort_clone' => true,
               'fields' => array(.....)

I clone many groups but when I save I lost the last 20 groups I created. Why? there is a limit for clone? I try to set max_clone to 1000 but don't work.