(Slim\Http\Request), Ob" while reading response header from upstream, client: 130.75.xxx.xxx server: studip.uni-hannover.de, request: "GET /plugins.php/meetingplugin/api/rooms/join/<course_id>/<room id> HTTP/2.0", referrer: "https://studip.uni-hannover.de/plugins.php/meetingplugin/...