For mapping it’s OK. And the request which goes to SAP – has all elements with data? Or some of them are empty?
Data types are suitable to data types in SAP?
Those are only things I can think of. Are you the “SAP side” by yourself? or it’s other company/guys? maybe ask them – if there’s any way to read logs on SAP side? Do they have logs? Did the request gets to SAP? things like this – I would check.