The BorderColor doesn't work.

Header and Footer Templates cover the fist and last item in the drop down.

When there are multiple ComboBox controls on the screen with IsEditable set to "True". After clicking the combo or typing a keyword the cursor starts blinking as the focus gets stolen. This freezes the application and requires it to be restarted.

In RadComboBox, when entering text to filter the items in dropdown, it would be nice to have the first item selected by default that matches the filter and also have the ability to select different item by keyboard up/down arrows.

This feature probably does not make sense on mobile platforms, but it would be great on desktop platforms.