I have found that if you are using the ToolProvder for multiple RadEditors that the undo redo functions do not update the content when pressed ore selected from the Undo / Redo toolbar buttons or dropdowns.
The undo / redo works for the RadEditor that is the ToolProvider but not for any that use the first editors toolbar.
This can be replicated on your demo site.
- Tick Use Tool Provider
- Click apply settings
Type some content in the first editor, press undo - Text entered is removed
Type some content into the second editor, press undo - no changed to the text in this editor.
Note: The dropdown menu still contains a history of undo/redo commands