Thank you for writing.
The provided sample project is greatly appreciated. I have logged it in our feedback portal
and I have added a vote for it on your behalf. You can track its progress, subscribe for status changes and add your comments on the following link - feedback item
I have also updated your Telerik points.
Currently, the possible solution that I can suggest is to trigger opening/closing the drop down in order to synchronize the selected item. A sample code snippet is available in the referred feedback item.
I hope this information helps. Should you have further questions I would be glad to help.
Telerik by Progress
Check out the Windows Forms project converter, which aids the conversion process from standard Windows Forms applications written in C# or VB to Telerik UI for WinForms.For more information check out this blog post
and share your thoughts.