The ComboBox displays the value as a text on load, because it considers it as a custom one. In other words, when source is loaded and the current selected value is not there then it will be considered as a custom one. If you would like to avoid this behavior, then you will need to set the selected value and text using the corresponding value
options. Here is a Dojo demo
(http://dojo.telerik.com/@ggkrustev/AQudA) that demonstrates this approach.
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