3358549 - Not able to change Tax Classification in Billing Document - S/4HANA Cloud

Customer wants to change the Tax Classification in Billing Documents, Sales Orders or Preliminary Billing Documents but the field is grey out. 

SAP S/4HANA Cloud 

This functionality is not available. 

Currently there is no way to change the material classification of the material at later stages. 

tax classification, sales order, billing document, change tax classification, F1602  , KBA , SD-BF-TX-2CL , Taxes (Public Cloud) , Problem