LexikJWT return a valid token with invalid credentials

Question

My API was working well with classic JWT settings. But as I am trying to make a frontend ux for it, I'm trying to switch the bundle to cookie mode. I changed my lexik_jwt_authentication.yaml like this :

lexik_jwt_authentication:
    secret_key: '%env(resolve:JWT_SECRET_KEY)%'
    public_key: '%env(resolve:JWT_PUBLIC_KEY)%'
    pass_phrase: '%env(JWT_PASSPHRASE)%'
    token_ttl: 3600
    remove_token_from_body_when_cookies_used: false //will remove that line once everything work fine
    
    token_extractors:
        cookie:
            enabled: true
            name: BEARER
    
    set_cookies:
        BEARER: ~

And my security.yaml :

security:
    password_hashers:
        Symfony\Component\Security\Core\User\PasswordAuthenticatedUserInterface: 'auto'
    providers:
        app_user_provider:
            mongodb: 
                class: App\Document\User
                property: username
    firewalls:
        login:
            pattern: ^/login
            stateless: true
            json_login:
                check_path: /login_check
                success_handler: lexik_jwt_authentication.handler.authentication_success
                failure_handler: lexik_jwt_authentication.handler.authentication_failure
        api:
            pattern: ^/
            stateless: true
            jwt: ~

    access_control:
        - { path: ^/login, roles: PUBLIC_ACCESS }
        - { path: ^/admin, roles: ROLE_ADMIN }
        - { path: ^/, roles: IS_AUTHENTICATED_FULLY }

And in case it's helpful my routes.yaml :

controllers:
    resource:
        path: ../src/Controller/
        namespace: App\Controller
    type: attribute
api_login_check:
    path: /login_check

When I'm trying to log in with Postman, everything works well. Except it is also working when I submit invalid credentials. API do return a 401 error with "Invalid credentials" in the response's body, just like before. But I also get a working token in a cookie. What's wrong with my setup ?