"Not able to select Business Unit while running Load Transactions"

Summary:

We are implementing Customer Promotion channel Program. We are able to create and activate Customer Channel Program (Promotions) and ship orders for the customer. As a next step, when we run "Load Transactions" ESS job, we are not able to select Business Unit which is a mandatory parameter. User is having Load Transactions (CJM_LOAD_TRANSACTIONS_PRIV) privilege with a custom role which inherits all privileges from Channel Operations. User also has data access to the BUs where we have created Channel Programs and Sales Orders. Please suggest what could be potential reason why we are not able to select Business