Maintain Primary flags issue

Hi Team,

We have an employee with multiple jobs, and both are termed and rehired several times since 2003. However, employee record 1 is the current primary job, and 0 record is a secondary one. But, Rebuild primary job flags process resetting it incorrectly to employee record 0 as a primary job. Does anyone know why is it happening?

Additional info: Employee record 0 initially hired in 2003, but later termed and started another job which is under empl Rcd 1.

Thank you,

Sandeep