Support for Drupal 7 is ending on 5 January 2025—it’s time to migrate to Drupal 10! Learn about the many benefits of Drupal 10 and find migration tools in our resource center.
I didn't have the time to search out the details of this issue but it seems like cnr doesn't do his job correctly on multiple value noderef that have checkboxes as a widget, only the first item is synced.
grts
Frederic