Hi
I allready solved the problem.
The issue is that I used, for testing purpose, email-adresses that I archived in Mailchimp.
But when you do so, the email-adress will be taken out of the argive with the data that it allready had.
After full delete from the contacts in Mailchimp, it worked.
So only firstname is passed through the API, and not the lastname.
Thank you for responding.
Hans
