The IsBusy property of RadBusyIndicator does not correctly reflect the value of its data-bound source when the control is unloaded and then loaded again while using a OneWay binding.

A common scenario where this occurs is when RadBusyIndicator is hosted inside a TabItem of a TabControl:

1. IsBusy is bound (OneWay) to a ViewModel property whose value is True.
2. The user switches to another tab, causing the RadBusyIndicator to be unloaded.
3. During the unload process, the control internally sets its IsBusy property to False.
4. The ViewModel property remains True.
5. When the user navigates back to the original tab, the RadBusyIndicator is loaded again.
6. Although the bound ViewModel property is still True, the control's IsBusy property remains False.
   
   

The binding is not re-evaluated when the control is loaded again, resulting in the control displaying a stale value that is out of sync with the bound ViewModel property.

The busy animation keeps running on the background when the busy indicator control gets unloaded (removed from the visual tree).

To work this around, set the IsBusy property of RadBusyIndicator to False in its Unloaded event handler.