The issue is reproduced with Marathi IME. Type some letters, press and release shift, then press space. The result is that the current IME text is duplicated.
Posted on:28 Nov 2014 14:02
With our latest Q3 2014 release we introduced an API that allows implementing custom support for different IMEs.
For further reference check the realted SDK demo: https://github.com/telerik/xaml-sdk/tree/master/RichTextBox/CustomCaret
The Telerik Team