Automatic Creation of Business Partner not working

Dear experts,

I need your advise on how to set up the automatic creation of Business partners when a customer is created.

When I set up new number ranges and make the proper customizing the replication is working fine. But when I try to assign number ranges that already exist I get no replication.

Example

Creating New number range XX from 5000 to 5999 from the beginning it works

If I try using an existing number range YY from 6000 to 6999 with current number 6089 it does not work.

Of course I made sure both customer and BP NRs are the same, etc..

Can you please advice?

Regards.