3736950 - Duplicate Tax ID Block is not consistently enforced between Fiori app Manage Business Partner Master Data and GUI app Maintain Business Partner in SAP S/4HANA Cloud Public Edition

• Duplicate Check has been set for the corresponding tax number category in the configuration activity "Maintain Tax Number Categories" (SSCUI 102415) and message 400 has been set as an error message in the configuration activity "Change Message Control for Duplicate Tax Numbers" (SSCUI 103601).
• In Fiori app Manage Business Partner Master Data, the whole process works successfully.
• In GUI app Maintain Business Partner, the error message appeared but the duplicate category can be saved.

SAP S/4HANA Cloud Public Edition

This rule is just for Manage Business Partner master data and not for GUI app Maintain business partner. This is a standard behavior. 

KBA 2886241 - How to Change Duplicate Tax Number Category from an Info Message to an Error Message in SAP S/4HANA Cloud Public Edition 

KBA 2886187 - How to Activate Tax Number Category Duplication Check for Business Partners in SAP S/4HANA Cloud Public Edition 

duplicate tax id, tax id block, business partner, manage business partner master data, maintain business partner, maintain business partner, duplicate check, validation gap, inconsistency,  tax number, duplicate control , KBA , LO-MD-BP-2CL , Business Partners for Public Cloud , Problem