I have a problem about executing a callback function. I just created an helper function to be used for by router and internal purposes. Helper function is working perfectly for the router part (tried with postman) but when I try to execute helper function alone, problems arise.

const MyModel= require('../model/MyModel');
const ERR_REASON = {
    SERVER: 'SERVER_FAULT',
    DB: 'DB_FAULT',
};



 const getCommunicationDiagnosticsHelper =function (start, end, cbf) {
        /*
        If I execute my callback function here, it works
        */
        MyModel.aggregate([
            //aggregator operators are passed here,
            //I'm not providing the pipeline operators list but they work fine!
        ])
            .allowDiskUse(true)
            .exec(function (err, results) {
                // START-This part of code is never executed in my function
                if (err) {
                    cbf(true,ERR_REASON.DB,null)
                }

                try {
                    cbf(false,null,results)
                } catch (error) {
                    cbf(true,ERR_REASON.SERVER,null)
                }
                // END-This part of code is never executed in my function
            });
    };

This works fine,

function cb(err,info,data){
  console.log({err,info,data})
  //supposed everything went well
  //this refers to `res`
  this.status(200).json(data)

}
const getCommunicationDiagnostics = function (req, res, next) {
    // start and end variables are to be used in aggregation.
    // parseDate is a simple utility function,
    const { start, end } = parseDate(req.params.interval);
    getCommunicationDiagnosticsHelper(start, end, cb.bind(res))
};
//router.js

const router=require('express').Router();
router.get('/com_diagnostics',getCommunicationDiagnostics)

But this doesn't. I expect the callback function (as argument) to execute, but it is not executing.

getCommunicationDiagnosticsHelper('2021-01-19T19:59:59.999Z','2021-01-20T19:59:59.999Z',(err, info, data) => {
    //This part of code is never reached!
    console.log({err,info,data});
})

Why does the helper function complete execution even though the callback function is not executed?