Thanks for your help. But setting the IsContentPreserved property to True hasn't changed anything.
We want to display Azure Service Reports in the HtmlPlaceholder so we can't use RadRichTextBox. I have added an Example in which two websites are displayed in HtmlPlaceholder and RadPaneGroup. If you switch between those two Tabs, the RadHTMLPlaceHolder reloads the displayed page (whether
How can we avoid this reload?