CB AutoActions: trigger to execute query before user registration saved

Hello

We have users who register with a temporary membership. Later they can decide to register as a full member. So when they register as full member there maybe exists already a user profile in Joomla and CB with probably the same email and username (because we use email as username).
The temporary membership is more a technical one and these users don't know that they are "temporary members". That's why we don't want to update the profile but rahter to create a new one for full membership.
So what I want to do is change username and email of the "old" user profile before CB makes the registration.

I made an auto action type query and tried various triggers.

 

The query sets a new username, email and password to the user already saved with the same email like entered on registration form (CB_PRIVATE_EMAIL).

 

Result:
The query is executed, but the insert of the new user results in an error: username already in use (UE_USERNAME_NOT_AVAILABLE).

Joomla 4.4.0
Community Builder 2.8.1

Am I maybe wrong with the triggers I chose / which one would be appropriate?
Is it possible to make changes in the database before CB checks if there is already a user registered?

Thank you and regards,
Anita

onStartSaveUserRegistration should be early enough to do that. The other 2 triggers won't be early enough. The problem will be your substitution [cb_private_email] won't work on onStartSaveUserRegistration as the user object isn't built yet. You'll need to access the POST data of the registration form directly. Try using [post_cb_private_email] assuming that field is available during registration.