Issue #2891276 by hmendes, mparker17, agiraud, paulmckibben, jessicacs:...

        continue;

      }

      // If the state is "checked" or "not checked", and the dependent form

      // field is a container (i.e.: the form field wrapper around a checkbox or

      // radio button), and there is a checkbox or radio button deeper in the

      // array, we actually need to use the (deeper) checkbox or radio button

      // because it is not possible to set a checked state on a container.

      if (count(array_intersect(['checked', '!checked'], array_keys($states))) > 0

        && $dependent_form_field['#type'] === 'container'

        && isset($dependent_form_field['widget']['value']['#type'])

        && in_array($dependent_form_field['widget']['value']['#type'], ['checkbox', 'radio'])

      ) {

        $dependent_location = array_merge($dependent_location, ['widget', 'value']);

        $dependent_form_field = $dependent_form_field['widget']['value'];

      }

      // Save the modified field back into the form.

      NestedArray::setValue($this->form, $dependent_location, $dependent_form_field);