Get Lookup Field and update Description Field

Get Lookup Field and update Description Field

Hello,
I'm trying to update the description field using this script on Field Change:

// Retrieve initial values of fields
var employee_name = $CS.getValue("ServiceReq_User_UDF_CHAR1");
var responsible = $CS.getValue("WorkOrder_Fields_UDF_CHAR4");
var type_asset = $CS.getText("WorkOrder_Fields_UDF_CHAR5");
var mobile_phone = $CS.getText("WorkOrder_Fields_UDF_CHAR7");
var additional_notes = $CS.getValue("WorkOrder_Fields_UDF_CHAR6");

// Update description with initial field values and user-added notes placeholder
var new_desc = "Please fill mandatory fields (with <span style='color: #FF8888;'>*</span>) related to the services required for our new employee" + "<br>" +
"<br>" +
    "You set" + ":" + "<br>" +
    "Employee Name: " + employee_name + "<br>" +
    "Responsible: " + responsible + "<br>" +
    "Type of Asset: " + type_asset + "<br>" +
    "Mobile Phone: " + mobile_phone + "<br>" +
    "<br>" +
    "----------Additional Notes-----------" + "<br>" +
    "Notes: " + additional_notes + "<br>";

$CS.setDescription(new_desc);

// Listen for changes in fields and update description accordingly
$CS.addOnChange("ServiceReq_User_UDF_CHAR1", function() {
    var updated_employee_name = $CS.getValue("ServiceReq_User_UDF_CHAR1");
    new_desc = new_desc.replace(employee_name, updated_employee_name);
    $CS.setDescription(new_desc);
    employee_name = updated_employee_name;
});

$CS.addOnChange("WorkOrder_Fields_UDF_CHAR4", function() {
    var updated_responsible = $CS.getValue("WorkOrder_Fields_UDF_CHAR4");
    new_desc = new_desc.replace(responsible, updated_responsible);
    $CS.setDescription(new_desc);
    responsible = updated_responsible;
});

$CS.addOnChange("WorkOrder_Fields_UDF_CHAR5", function() {
    var updated_type_asset = $CS.getText("WorkOrder_Fields_UDF_CHAR5");
    new_desc = new_desc.replace(type_asset, updated_type_asset);
    $CS.setDescription(new_desc);
    type_asset = updated_type_asset;
});

$CS.addOnChange("WorkOrder_Fields_UDF_CHAR7", function() {
    var updated_mobile_phone = $CS.getText("WorkOrder_Fields_UDF_CHAR7");
    new_desc = new_desc.replace(mobile_phone, updated_mobile_phone);
    $CS.setDescription(new_desc);
    mobile_phone = updated_mobile_phone;
});

$CS.addOnChange("WorkOrder_Fields_UDF_CHAR6", function() {
    var updated_additional_notes = $CS.getText("WorkOrder_Fields_UDF_CHAR6");
    new_desc = new_desc.replace(additional_notes, updated_additional_notes);
    $CS.setDescription(new_desc);
    additional_notes = updated_additional_notes;
});

The Responsible field, is retreived by a lookup using the script on Form Load:
$CS.referField("WorkOrder_Fields_UDF_CHAR4","users",{url:"/api/v3/users"});

Every time a Field change, the description is updated with relative text, but not for responsible. Can you help me to found which is the issue?

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