3507203 - Tax numbers assigned to custom tax categories are not saved into customer/vendor related tables (KNA1/LFA1)

A custom tax category is created and assigned to business partner, under "Identification" tab.
When checking tables KNA1/LFA1, tax number assigned to this custom tax category is not saved.

•Sales And Distribution (SD)
•Logistics Execution (LE)
•SAP R/3
•SAP R/3 Enterprise 4.7
•SAP ERP Central Component
•SAP ERP
•SAP Enhancement package for SAP ERP
•SAP Enhancement package for SAP ERP, version for SAP HANA
•SAP S/4HANA

Custom tax category, tax category, VAT, KNA1, LFA1, STCEG, STCD1, STCD2, STCD3, STCD4, STCD5, BP, Identification, tax number, TFKTAXNUMTYPE, TFKTAXNUMTYPEC, DFKKBPTAXNUM. , KBA , CRM-BF-TAX , Tax Determination , Problem