var mongoose = require('mongoose');
var Schema = mongoose.Schema;
//broken schema
var coursesSchema = new Schema({
    college: {
        type: String,
        required: true
    },
    units: {
        type: Number,
        required: true
    },
    course_code: {
        type: String,
        required: true
    },
    course_name: {
        type: String,
        required: true
    },
    class_number: {
        type: String,
        required: true
    },
    section: {
        type: String,
        required: true
    },
    class_day: {
        type: String,
        required: true
    },
    time_start: {
        type: String,
        required: true
    },
    time_end: {
        type: String,
        required: true
    },
    faculty: {
        type: String,
        required: true
    }
});


module.exports = mongoose.model('Courses', coursesSchema);

//working schema
var mongoose = require('mongoose');
var Schema = mongoose.Schema;


var loaSchema = new Schema({
    process_name: {
        type: String,
        required: true
    },
   process_details: {
       type: String,
       required: true
    },
    process_deadline: {
        type: String,
        required: true
    },
});


module.exports = mongoose.model('LOA', loaSchema);

I have this schema which I export into index.js file. This schema works in other parts of the code except in index.js. When I query Courses schema, it returns model.find() is not a function. When I try creating a new Courses object it says Constructor is not a schema. I have other schemas that work fine inside index.js and I get to query them, but this schema is an exception.

Does anyone know the reason behind this?