Pre-request script newman syntax error

My question:
I have a small collection with a few requests. As all requests require a JWT Token I implemented a method in collection pre-request scripts that makes the authorization requests and stores the token as an environment variable.
Along with this method I have a few common test methods like schema validation, etc.
If I run the collection using postman, postman runner or newman on my machine everything works as expected.
If I put the newman execution inside a step in a Jenkins pipeline (Linux machine) I get an error “Unexpected token { in pre-request script”

Details (like screenshots):

/******************************************
GLOBAL FUNCTIONS USED IN ALL TESTS
******************************************/

utils = {

    validate_response_code: function(pm, expected_code) {
        pm.response.to.have.status(expected_code)
    },

    validate_response_is_json: function validate_response_is_json(pm)
    {
        var json_response = null;
        try
        {
            json_response = pm.response.json();
        } catch {
            json = null;
        } finally {
            console.log(json_response);
            pm.expect(json_response).not.eq(null);
        }
    },

    validate_response_is_not_json: function validate_response_is_not_json(pm)
    {
        var json_response = null;
        try
        {
            json_response = pm.response.json();
        } catch {
            json = null;
        } finally {
            console.log(json_response);
            pm.expect(json_response).eq(null);
        }
    },

    validate_schema: function validate_schema(pm, schema)
    {
        var response_data = pm.response.json();
        var Ajv = require("ajv");
        var ajv = new Ajv({logger: console}, schema);
        pm.expect(ajv.validate(schema, pm.response.json()), JSON.stringify(ajv.errors)).to.be.true;
    },

    get_error_schema: function get_error_schema()
    {
        const schema = {
	        "type": "object",
	        "properties": {
                "timestamp": {
                    "type": "string"
                },
                "status": {
                    "type": "integer"
                },
                "error": {
                    "type": "string"
                },
                "message": {
                    "type": "string"
                },
                "path": {
                    "type": "string"
                }
            },
            "required": [
                "timestamp",
                "status",
                "error",
                "message",
                "path"
            ]
        };
        return schema;
    }
}

/******************************************
END OF GLOBAL FUNCTIONS USED IN ALL TESTS
******************************************/

// Local use variables
var is_patch_ok = false;
var is_post_ok = false;
var token = null;

// Environment variables
var debug = pm.environment.get("debug");
var host_sts = pm.environment.get("host_sts");
var client_id = pm.environment.get("client_id");
var client_secret = pm.environment.get("client_secret");
var admin_user_id_sts = pm.environment.get("admin_user_id_sts");
var admin_user_password_sts = pm.environment.get("admin_user_password_sts");

// Iteration data variables
// If not set in iteration data, we are executing this in Postman, so we get the value from environment
var user_global_id = pm.iterationData.get("user_global_id");
if (user_global_id === undefined)
{
    user_global_id = pm.environment.get("user_global_id");
}

// Calculated variables
var url = host_sts + "/admin/client/" + client_id;
var basic_auth = admin_user_id_sts + ":" + admin_user_password_sts;
var auth_header = "Basic " + CryptoJS.enc.Base64.stringify(CryptoJS.enc.Utf8.parse(basic_auth));

// Variable logs
if (debug == "true")
{
    console.log(client_id);
    console.log(client_secret);
    console.log(admin_user_id_sts);
    console.log(admin_user_password_sts);
    console.log(basic_auth);
    console.log(url);
    console.log(auth_header);
}
// START STEP 1 (PATCH) EXECUTION
pm.sendRequest({
    url: url,
    method: 'PATCH',
    header: {
        'Authorization': auth_header,
        'Accept': 'application/json',
        'Content-Type': 'application/json'
    },
    body: {
        mode: 'raw',
        raw: JSON.stringify(
            {
                userId: user_global_id,
                extraClaims: {
                    sec_mode: "platform",
                    country: "XXXXXXXXXXXXXXXXXX",
                    local_realm: "XXXXXXXXXXXXXXXXX"
                },
                audience: [
                    "XXXXXXXXXXXXXXXXXXX"
                ]
            }
        )
    }
}, function (err, res) {
    if(res.code === 204)
    {
        if (debug == "true")
        {
            console.log("\tPATCH execution succeeded");
        }
        // Execute Step 2 of authentication once the first request is complete and correct
        // Calculated variables
        let url = XXXXXXXXXXXXXX;
        let basic_auth = client_id + ":" + client_secret;
        let auth_header = "Basic " + CryptoJS.enc.Base64.stringify(CryptoJS.enc.Utf8.parse(basic_auth));
        if (debug == "true")
        {
            console.log(basic_auth);
            console.log(url);
            console.log(auth_header);
        }
        pm.sendRequest({
        url: url,
        method: 'POST',
        header: {
            'Authorization': auth_header,
            'Accept': 'application/json',
            'Content-Type': 'application/json'
        },
        body: {
            mode: 'raw',
            raw: JSON.stringify(
                {
                    userId: client_id,
                    extraClaims: {
                        sec_mode: "platform",
                        country: "XXXXXXXXXX",
                        local_realm: "XXXXXXXXXX"
                    },
                    audience: [
                        "XXXXXXXXXXXXXXX"
                    ]
                }
            )
        }
        }, function (err, res) {
            if(res.code === 200)
            {
                let response = res.json();
                is_post_ok = true;
                let token = response.token;
                // Save the token to environment for further uses
                token = "Bearer " + token;
                pm.environment.set("token", token);
                if (debug == "true")
                {
                    console.log(token);
                }
            } else {
                console.log("\t\tError executing POST.")
                console.log(res);
                console.log(err);
            }
        });
    } else {
        console.log("\tError executing PATCH.")
        console.log(res);
        console.log(err);
    }
});

I’ve already tried: