This problem is even reproducible in our Demo application >> Virtual Grid >> Web service example. You will notice that when you scroll to the bottom, the waiting indicator is not being animated when the DPI scaling is higher than 100%.
If you apply the same gif file in a PictureBox it gets animated when using 150% DPI scaling.
Please refer to the attached sample project and follow the steps illustrated in the gif file.
Note: if the vertical scrollbar is visible, the editor is activated as expected.
Me.RadListView1.ItemSize = New Size(200, 30)