keep Primary quantity and secondary quantity consistent

Hi experts

In 12.1.3.

The primary_uom_code is weight,  secondary_uom_code is Each, conversion_rate=1.320467

Do inventory transactions, enter seondary quantity and primary quantity populated automatically. primary_quatity=secondary_quantity*conversion_rate

In onhand quantity, the secondary quantity is zero, but primary quantity is not zero(more than zero or negavtive).

Is there any way to prevent this issue happen? When secondary quantity is zero, but primary quantity is not zero, how to solve?

Thanks

Fengling