Error while nullify Business unit and click on continue in local and global transfer

Summary:

We have written the field defaulting auto complete rule to nullify Business Unit, Job and some DFF fields while making Global transfer. These fields are became null when we go to the section as expected in the transaction, but after selecting new Business Unit, Job and other required fields and click on continue button, it says the below error message even when we have selected value in that field.

Error:

"Attribute BusinessUnitId in EmployeeAssignmentDEO is required"