Issue With Dropdown List From Expression Rule and save to CDT

Hello All, 

I am a newbie to the Appian Development.  I am trying to display the results of an expression rule (that is a CDT based on a database view) as choice labels and values and try to save the selected value to another CDT ( database table). The issue that I am facing is I get an error when trying to display it in the form and I get the below message: 

A dropdown component [label=“Mfg Ship Methods”] has an invalid value for “value”. All selected values must be present in the choiceValues array, but value was 000001_AIR USA_A_US and choiceValues was 000001_AIR MEX_A_MEX; 000001_FED_P_FEA.

Here my table CDT already has an existing value of 000001_AIR USA_A_US in the database. Below is my configuration for the dropdown component: 

a!dropdownField(
label:"Mfg Ship Methods",
choiceLabels: if(rule!EXP_GetMfgShipMethods(local!pagingInfo,ri!expediteline.request_line_id).totalCount >0,index(rule!EXP_GetMfgShipMethods(local!pagingInfo,ri!expediteline.request_line_id).data,"mfg_ship_method",null),{}),
choiceValues: if(rule!EXP_GetMfgShipMethods(local!pagingInfo,ri!expediteline.request_line_id).totalCount >0,rule!EXP_GetMfgShipMethods(local!pagingInfo,ri!expediteline.request_line_id).data.mfg_ship_method,{}),
value: ri!expediteline.final_ship_method,
saveInto: ri!expediteline.final_ship_method
)

Any insight is appreciated!

Thanks