Null is set after RadCombobox value selected changed

[Harshal]

Hi,

We are using virtualized Radcombobox in our project. since virtualization does not support filtering so we have created custom filtering mechenism by extending RadCombobox and defined new VirtuzalisedRadCombobox.

We placed this VirtuzalisedRadCombobox in CellEditTemplate. But when we select new value from drop down, then selected value gets null and also itemsource gets null.

Can anybody please let me know whats the reason of the issue.

Thanks,