Is this a Vercel bug? Cannot find module './model'

I have 2 files:

• controller.js
• model.js

I'm making an express.js app.

So, model.js is required inside controller.js but I have this error when I call my api

And the logs are:

But here is the problem, './model.js' really does exist, but vercel doesn't recognize it And works fine in local development and it is required correctly

this is model.js

const { nanoid } = require("nanoid");

const getDateStr = () => {
    const now = new Date();
    return `${now.getFullYear()}-${now.getMonth()+1}-${now.getDate()}`;
}

const Purchase = ({ id_user_buyer, id_user_seller, id_product, quantity }) => (
    {
        id_user_buyer,
        id_user_seller,
        id_product,
        quantity,
        id_purchase: nanoid(),
        date: getDateStr(),
    }
);

module.exports = {
    Purchase
}

And this is controller.js

const err = require("../../../utils/error");
const { Purchase } = require("./model")
// others modules and they are well imported, so the problem is './model'
const userController = require("../user");
const productController = require("../product");
const cartController = require("../cart");

const TABLE = 'purchase';

function purchaseController(injectedStore) {
    // example code
    async function makePurchase(data) {
        const purchase = Purchase(data);
        await injectedStore.insert(TABLE, purchase);
    }
    
    return {
        makePurchase,
    }
}

module.exports = purchaseController;

As you can see, model.js is well imported inside controller.js I don't know why vercel says ERROR Cannot find module './model' I say it again, works fine in local development but not in vercel

A quick fix is copy and paste all the code of model.js inside controller.js I tried it, I deploy him and it worked. All my app also works fine if I just comment that line where I import ./model , but obviously my application would stop having that functionality, so the first solution is uggly but works, but those are not the best solutions. the best solution is for the file to be imported correctly

Curious fact I tried renaming the file and it didn't help either. It also doesn't work if I import a new file.

NOTE I changed the nodejs version from 12 to 14, will that have something to do with it?

root

api

this is my vercel.json

{
    "version": 2,
    
    "builds": [
        {
            "src": "/api/index.js",
            "use": "@vercel/node"
        }
    ],

    "routes": [
        {
            "src": "/api/auth(.*)",
            "dest": "/api/index.js"
        },
        {
            "src": "/api/users(.*)",
            "dest": "/api/index.js"
        },
        {
            "src": "/api/products(.*)",
            "dest": "/api/index.js"
        },
        {
            "src": "/api/cart(.*)",
            "dest": "/api/index.js"
        },
        {
            "src": "/api/purchases(.*)",
            "dest": "/api/index.js"
        },
        {
            "src": "/api/sales(.*)",
            "dest": "/api/index.js"
        }
    ]
}

I don't know if it's a vercel bug or it's a mistake on my part. My application works currently but doing the trick that I named before, which was about putting all the code of model.js inside of controller.js

Thanks for reading the whole issue.