We can confirm that this is a bug and therefore we logged an item in our Feedback Portal. In the portal, you can track the status of the feedback item. We have also updated your Telerik points as a small appreciation for bringing this issue to our attention.
Regards,
Dinko
Telerik by Progress
Want to extend the target reach of your WPF applications, leveraging iOS, Android, and UWP? Try UI for Xamarin, a suite of polished and feature-rich components for the Xamarin framework, which allow you to write beautiful native mobile apps using a single shared C# codebase.