I've been messing around with this MultiSelect widget. It has been a little buggy after the Q3 2015 release. I'm saying so because this is not the first time I'm seeing and reporting a problem with this widget.
So, If you please go to this link - http://dojo.telerik.com/OSoTU/4
- Type "cha" in the multiselect control, and wait for 2 seconds to see the matching products,
- Go ahead and choose one item from the products,
- Now, hit "Populate Items" button to add one more item to the widget.
It does not add it for the first time, but you can see the textbox has updated values. Now, if you hit the button again, it will show you the right items in the widget.
And this behavior can only been seen If serverFiltering is active.