Since you were not able to tell us exactly which control you're having trouble with, I surmise you're referring to the RadAutoCompleteBox. There is an easy fix for what your describing.
You can set the PopupCloseMode
by which the dropdown closes,
(which is what you're experiencing now)
If you set it to OnBackKeyPress, it will stay open when the user taps another UI element. Here's how to set it:
If you have any further questions, please let us know.
Lance | Tech Support Engineer, Sr.
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