When the RadToolTip's ManualClose
property is set to true the tooltip hides when the user clicks on the close button. This behavior is by design and in this case the AutoCloseDelay
properties' settings do not affect the control.
You can use ShowEvent="FromCode" and the rich RadToolTip' client-side API in order to build your own custom logic for showing and hiding the tooltip when you want.
the Telerik team