Could you please confirm whether you are facing the tab index issue after applying the provided jQuery workaround?
I have tried to replicate the twice tabbing problem in order to go to the next control but no avail. I have attached a sample project that shows a RadWindow control when user clicks on the button. Once the RadComboBox got focused, only one click on the Tab button is needed to go to the next control within the RadWindow. Probably you have some other controls on the page or your scenario is different than the attached sample project. Could you please clarify whether you are reproducing that unusual behavior with the attached simplified page?
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