Your ROOT_URL in app.ini is https://source.parasitstudio.de:63000/ but you are visiting https://source.parasitstudio.de/wirtz/AutoConnect/blame/commit/a987caf4988303cefef561374c8c907514519cfd/library.properties
You should set ROOT_URL correctly, otherwise the web may not work correctly.
paragraph=A library for easy implementing the Web interface constituting the WLAN for ESP8266 WiFi connection. With this library to make a sketch which connects from ESP8266 to the access point at runtime by the web interface without hardcoded SSID and password.