Widget 5 Events does not display German Umlaute ÄÜÖ

  • Platform information:
    • Hardware: Intel Core i5
    • OS: Windows 10 Pro
    • Java Runtime Environment: Zulu
    • openHAB version: 2.5
  • Issue of the topic:
    I have installed the CalDavio Binding to display my Waste Calender Events.
    It is working over all, and i could display it correct in BasicUI.
    But i want to use it in my HabPanel, and installed the Custom Widget: Calendar - 5 Upcoming Events from the Widget Gallery.
    It works also, but the German Umlaute are not displayed correct.
    It should be Restmüll (works in BasicUI and also in the used Calender) but in the Habpanel in the Widget it is displayed as Restm?ll

I was locking inside the json File, but my Knowledge is not enough to fix this…
Could you please help me, or point me to the right Direction how to fix this?

Thank you!