Auth0 generates JWT in local environment and JWE in production environment Next

I am using Auth0 for authentication in my Next.js app with an Express.js API backend. Everything works fine in my local environment, but when I deploy my application to production, I encounter authentication issues.

When I request an access token from Auth0 in my local environment, I receive a JWT (JSON Web Token), which works as expected. However, when I request an access token from Auth0 in my production environment, I receive a JWE (JSON Web Encryption) token instead. This causes authentication problems, as my backend expects a JWT token.

I have double-checked my environment variables and Auth0 settings, but I cannot find the cause of this discrepancy. How can I ensure that Auth0 generates a JWT access token in both my local and production environments?

My jwt checking in the backend:

const { auth } = require('express-oauth2-jwt-bearer');
const jwtCheck = auth({
  audience: process.env.AUTH0_AUDIENCE,
  issuerBaseURL: process.env.AUTH0_ISSUER_BASE_URL,
  tokenSigningAlg: 'RS256'
});

My connection to auth0 in the front:

const auth0 = initAuth0({
    scope: 'openid profile email offline_access',
    audience: process.env.AUTH0_AUDIENCE,
    issuerBaseURL: process.env.AUTH0_ISSUER_BASE_URL,
    baseURL: process.env.AUTH0_BASE_URL,
    clientID: process.env.AUTH0_CLIENT_ID,
    clientSecret: process.env.AUTH0_CLIENT_SECRET,
    secret: process.env.AUTH0_SECRET
});

Any help would be greatly appreciated.
Thanks

I've verified my env variables in both environments and everything seems fine (to me at least).

UPDATE:
I've noticed something interesting in my local env. I have replaced all my process.env in my initAuth0 with the actual values of my .env file. And I removed my .env file. The auth connection is made, but I receive a JWE instead of a JWT. This is my production issue.

const auth0 = initAuth0({
    scope: 'openid profile email offline_access',
    audience: "***",
    issuerBaseURL: "***",
    baseURL: "http://localhost:3000",
    clientID: "***",
    clientSecret: "***",
    secret: "****"
});

But if I add AUTH0_AUDIENCE="***" in my .env file and keep all the values in initAuth0 (without the process.env, just the actual values), I get the correct JWT and everything works. Again, I'm talking about locally.

It seems like when trying to retrieve the JWT with getAccessToken(), the AUTH0_AUDIENCE is automatically accessed and therefore needed by Auth0. Again this works locally but not in production.

In Nextjs because of security in env file, if you want to get an env in client you have to put NEXT_PUBLIC in first of every env name like this:

Instead of AUTH0_AUDIENCE you must use NEXT_PUBLIC_AUTH0_AUDIENCE

Ok I've found out a way to fix this, I deployed my app to Vercel instead of AWS Amplify. I didn't change anything in the config and it worked.

I'm really curious if anyone has an idea on what I did wrong on AWS.