Hello Vito,
As you can see in the online demo, the handler, attached to the rate server event of the rating controls gets executed. I created a simple test page to double-check that there is no problem with the server event - please, find it attached. Could you please open a new support ticket and send me a simple running project, demonstrating the problem you have, together with detailed information on the steps I need to follow in order to reproduce it locally?
Best wishes,
Tsvetie
the Telerik team