"Invalid State" exception with PHP 8.0

Recently upgraded our stack to use PHP 8 and Laravel 8.22
This required an upgrade within composer of the Auth0 library:

   "auth0/login" From ""5.4" to "6.2"

The code snippet that creates the error is this:

        /** @var Auth0Service $service */
        $service = App::make('auth0');
        $profile = $service->getUser();

When trying to get the user, the app fails with

Auth0\SDK\Exception\CoreException
Invalid state 

The Auth0 logs online show a successfull login

At this point I have no idea how to debug this… where should I start.
Remember this was a perfectly fine working application before the version upgrade.