I'm guessing that by iterating through all the views contained within pnlContent what might be happening is that the ListView is actually returning not just the Listview but also the views contained within it and maybe this is what causes the error. Just my best guess!
Maybe trying checking if the View is a ListView before checking its position and size...
B4X:
Private Sub GetViewAtXY(X As Float, Y As Float) As Object
For Each v As View In pnlContent.GetAllViewsRecursive
If v Is ListView Then
If X >= v.Left And X <= v.Left + v.Width And Y >= v.Top And Y <= v.Top + v.Height Then 'this line is 469
Return v
End If
End If
Next
Return Null
End Sub