3697628 - eInvoice Belgium error: "Base quantity must be a Positive Number above zero" on submission in eDocument cockpit

During the process of eInvoice containing a free-of-charge item submission in Belgium DRC, the system raises error "Base quantity must be a Positive Number above zero" in eDocument Cockpit.  

• SAP S/4HANA Cloud Public Edition
• SAP Document and Reporting Compliance, Cloud Edition

Base quantity, free-of-charge item, e-Invoicing Belgium, Manage Electronic Documents, Price Condition inactive, Fix value price, BADI EDOC_ADAPTOR, SET_OUTPUT_DATA, EDOC_COCKPIT, eDocument cockpit, SAP S/4HANA Cloud Public Edition, DRC Cockpit, electronic document processing, e-invoice submission error,  eDocument, DRC, zero, Positive Number.  , KBA , CA-GTF-CSC-EDO-BE , Belgium , CA-GTF-CSC-EDO , Electronic Document Processing Framework , Problem