This column Account Group/Item is so very confusing for customers and consultants. It is not the account group, it is the non-stock item. The account group is tied to the account on these documents and could be labeled something else.
Also, now in 19.107 if this field doesn't match the Item on the budget, you get a warning - see attached. Again, this error is misleading because it is not the Account Group from the budget that doesn't match.