Hi there,
as Bing Maps is an Add-In, I am unsure, if it's an Office issue. But may be, you can forward the issue to the Bing Map Add-In team.
Please open Excel 2016 in German and add a new Bing Map object to a worksheet (Einfügen / Add-Ins / Binbg Map). Then, just insert the sample data when the Add-In asks for. After then, click on any pie chart element in the map. The window has a button, which is untranslated and should be Schließen.
Best,
Mourad
