WINPE 20H1 print screen capture doesn't capture all

Question

Can someone help me. I have a capture program it can capture all window(cmd window) in winpe 19H2, but winpe 20H1 fail as picture.

1. winpe boot into cmd window.
2. I use below code to capture window desktop all window.
3. I try to change GDI method program it has same problem.

VB: code
keybd_event(44, 0, 0, IntPtr.Zero)
Application.DoEvents()
Dim img As Image = Clipboard.GetImage
img.Save("test.png")
PictureBox1.Image = Image.FromFile("test.png")