Person address validation is not happening through HDL

When we trying to update address information like County, City. State, Postal code via the UI, the system is validating the address fields like which ever values are there in the LOV only those values we were able to provide.

But when we are trying to update/correct these address fields via HDL, the HDL is updating any random value it is giving which are not there in the LOV. Basically, it is not validating correctly.

Please help us in finding a solution for this.