Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/AutoConnect/src/commit/f1151ba33df66d1dbe0abd50830f8a01d996a633/examples/mqttRSSI_FS
You should set ROOT_URL correctly, otherwise the web may not work correctly.