Material Group Doesn't Save

Hi Gurus,

I am using BAPI_MATERIAL_SAVEDATA to create a new material. In one of our client systems the Material Group (MVGR1/MATL_GRP_1) populates as expected after running the BAPI and setting it in SALESDATA. However, when we run the same program in another client, the field ends up being blank. Any ideas as to why this may be? Is a configuration change necessary?

Thanks!