The k-ng-model directive was introduced, because ng-model
sets/gets the value of the underlying input element directly instead using the value method of the widgets, which in some cases break the widget behavior.
In this particular case, the ng-model didn't work because of a bug in the DropDownList. The latest internal build seems to work as expected with ng-model too. I would suggest you upgrade to the latest internal build that is available in your Telerik account and let us know if the problem still persists.
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