When I login in the backend. I have rights in the legacy but not in the new stack.
After https://github.com/ezsystems/ezpublish-legacy/pull/1373 the Session Name is wrong
Could you document a few steps how to reproduce the issue?
$container = ezpKernel::instance()->getServiceContainer();
$contentService = $container->get('ezpublish.api.service.content');
$content = $contentService->loadContent(123); //Content which the anonymous user has no rights => UnauthorizedException
Merged and fixed in: