Apple Configurator 2 - unexpected error/ failed to create activation request

Out of a sudden i get a unexpected error in Apple COnfigurator 2.

Procedure that we follow:

Mac with Apple Configrator 2 (a little older mac but is working always)

Profile created with a WIFI in it

Blueprint created

attached an iphone and choose prepare

after downloading activation ...step 3 an error occured, also tried several other Iphones with version 12.3 IOS.

In the profile i also choose a MDM server (Sophos Central). In the URL which i copied from device groups in Sophos Central, i put in the blueprint.

The after preparing the blueprint attache an iphone and choose: prepare or i connect the iphone and choose: blueprint - nameless - apply (nameless is the name for a blueprint i created), both methods could work?

after step 3 the error occurs, which method i choos makes no difference..

Every time i try this before i put the iphone connected to a wifi (that what i have found on the internet that can cause the error).

What can this be?