Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/AutoConnect/src/commit/659b68d3ffc09cae68f0a0e53369aa4bf751ab55/examples/mqttRSSI_FS
You should set ROOT_URL correctly, otherwise the web may not work correctly.