Why does this happen?
If the code in your welcome email is shown as **********, it is because the member already has a code in the system.
For security reasons, the system hides the existing code.
What does it mean?
When you see stars instead of a code, it means:
The member is already created in the system
A login code has already been generated for the user
The system is protecting existing login credentials
Has anything changed?
No, nothing has changed in how new members are created.
This is the normal behavior when a code already exists in the system.
Conclusion
The stars are not an error, but a security measure to protect existing codes.