Updating the Employee SAP user on the BP via infotype 105

Good day Experts

I came across your article: https://blogs.sap.com/2018/03/12/how-to-create-employee-in-s4hana-for-customer-management/

We have an issue now that we create the BP role Employee (BUP0003) and assign SAP USER via infotype 105 successfully.

Updating the SAP USER on the identification is not happening currently via infotype 105. Just wanted to know if you could possibly guide me in what the issue could be?

Many thanks