In iOS if you are on a page with a rich text editor, then navigate to a new page, the editor gets unloaded. When the user navigates back, the document is still unloaded and is no longer functional. This is not a problem on Android.
Here is a stack trace of when that document gets unloaded:
I set a minimum height on a RadRichTextEditor control so its height would expand as the user typed more into the editor. This caused different issues on both Android and iOS.
On Android: As the height attempts to expand, it gets caught in an infinite loop where the bottom of the height is shaking. I believe this is because the call to UpdateContentSize in OnSizeAllocated causes a re-render of the underlying webview, which causes it to keep resizing over and over.
On iOS: The editor height never expands, but I believe this might be a platform issue and not a telerik issue.