In the DropDownList and ComboBox, virtualization only works when the popup is open. In both widgets, item navigation is functional by pressing down to select the next item in the list without opening the popup. However, when the end of the first page of results is reached, the selection goes back to the top of the first page of results instead of loading the second page via virtualization. This misleads the user in that it only presents a portion of the options available. This is also an issue for disabled users and accessibility.
In both examples, holding down without opening the popup will never load more results.
We have had this issue in the past but it is a bigger issue now that we are focusing more on accessibility since users rely more heavily on keyboard navigation.