In order to prevent the opening of the Popup of the RadRibbonView, you can handle the PreviewPopupOpened event like so:
sender, Telerik.Windows.RadRoutedEventArgs e)
Collapsing the Popup on Mouse event cannot be implemented due to some internal setters in properties of the Popup.
Feel free to ask if you need further assistance.All the best,
the Telerik team
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