Your latest update 5.0.1 works!
I have made an extra automatic step to make notifications within a cronjob.
Because I use CN for a bulletinboard where users can post messages themselves, it is not feasible that I have to make notifications in de Joomla backend everytime.
So in a first cronjob I execute an SQL script that makes the necesary notifications (see uploaded image).
If you are interested to make this possible for al your users, I can upload the SQL code.
Thanks again for the quick help you gave.
Rob