While updating a custom menu field in cutom object, menu field is not updating

@Nika Gerson Lohman

I have used this script in my BUI while saving the record, but the menu field is not updating, for normal text fields i am able to update the data,can anyone please help on this.

function saveValidation(workspaceRecordEventParameter) {
    workspaceRecord.getFieldValues(['CO$ProblemRecord.Id', 'CO$ProblemRecord.ManagerApprovalStatus']).then(function (IFieldDetails) {

  

        _manager_Approval = IFieldDetails.getField('CO$ProblemRecord.ManagerApprovalStatus').getValue();


           // managerEmail = workspaceRecord.updateField('CO$ProblemRecord.ManagerEmail', managerEmail);

            if ((_manager_Approval == "[No Value]" ||  _manager_Approval == null)){

                workspaceRecord.updateFieldByLabel('CO$ProblemRecord.ManagerApprovalStatus.Id',2);


            }


});

}

@Nika Gerson Lohman, @Premkumar Sabarinathan-Oracle