Hello, just to add something to this discussion, I am having the same issue in version 2.14.0 of the components. In my specific case, I am posting up a dialog to get some initial information to add a record to the database. This dialog contains a dropdown containing names appropriate to the field. There is a button on the form which launches the dialog. If I am close enough to the top of the page (I haven't scrolled too far down to get to the button), the drop down renders properly:
If I scroll down far enough such that the button is now at the top of the browser page before clicking it, the drop down renders above the text area of the drop down:
In the second case, if I click the dropdown to close the list and click again to bring it back up, the list is still above the text area, but closer to the text area of the dropdown.