Employee Heritage' and 'Primary skill cluster' in 'Assignment' section disappear after filling

When admin try to fill the assignment details and when try to fill the Employee Heritage' and Primary skill cluster' in 'Assignment' section the fields get dissapear once filling each section. even though the fields are marked as visible and minatory.

this happening for the hire an employee, Add a Contingent Worker, Add a Pending Worker, Add a Nonworker sections facing the same issue