I managed to find the error.

Auth0 enforces namespacing for custom claims in tokens to avoid conflicts with standard OpenID Connect (OIDC) claims (like sub, email, name). If you want to include custom attributes (like user roles), you must prefix them with a unique, non-Auth0 domain.

I used my auth0 domain which lead to the trigger not working. After changing the namespace to a custom one it worked properly.