Dear Caetano,
As per your suggestion i tried to check with all active/inactive version but through that also it is not showing any demand in md62 screen same process i tried to test for multiple materials but demand is not updated but is showing as requirement already exist please find the bellow screen shots
Through change bapi i.e. BAPI_REQUIREMENTS_CHANGE it is working fine if requirement exist then go through this bapi it will change the requirement,Please guide why creation bapi is not working correctly i.e. demand not updated in MD61 or MD62
Regards,
Krishna.