Purchase Orders; Warehouse Line Item Issue

Got a question regarding Warehouse field on the PO Module. 

When creating a P.O we normally place warehouse ID where our material is supposed to be shipped to

The issue I'm having is when using a specific warehouse (above warehouse) when we delete the department number,
it defaults to the warehouse when using other warehouse codes... but in this case, it throws the below error

My question is:
What can I do in Sage 500 ERP to address the issue to behave as the other warehouses. I've gone into the
Warehouse Setup and compared the warehouses and there is no difference other than the GL Accounts

Any help is appreciated...