It should be noted that the Suitelet (and SuiteTalk for the same matter) uses a customform to update the records. So, it's important to assign the customform when inserting a record. If the customform being used does not have the valid select choices, for example entityStatus=6 (this is only available on Lead Forms, not on customer forms).
customer.setFieldValue('customform', 3); // Standard Lead form.
Suitelet
It should be noted that the Suitelet (and SuiteTalk for the same matter) uses a customform to update the records. So, it's important to assign the customform when inserting a record. If the customform being used does not have the valid select choices, for example entityStatus=6 (this is only available on Lead Forms, not on customer forms).
customer.setFieldValue('customform', 3); // Standard Lead form.