Take a photo every 5 seconds - vb.net

Question

I am developing a panel, which from time to time runs a process and generates an image within it. Once the image is generated, you need to take a photo to save it for the changes that are made.
I already developed the part where the images change, but when I take the photos, they all come out blank. Add a delay on the screen thinking that it should take a while to take the photo of the panel later, but it still comes out blank and if there is something inside the panel, since I am resizing it according to the size of what is updated.
Can you help me to see where my error is? Or guide me to obtain an optimal result?, I also tried using a timer, but it gives me the same result, any ideas?
This is the code developed.
sub buldimages()
Panel1.Refresh()
System.Threading.Thread.Sleep(5000)
segondGa(varName)
'Timer1.Start()
End Sub
Function segondGa(nameLine As String)
Dim widthOldPuno = Panel1.Width
Dim heightOldPuno = Panel1.Height
Dim widthOldPdos = Panel2.Width
Dim heightOldPdos = Panel2.Height
Dim coordenada, i As Integer
For Each obj As Control In Panel1.Controls
coordenada = obj.Location.X
Next
Panel1.Width = widthOldPuno + (coordenada - Panel1.Width)
Panel2.Width = Panel1.Width + 113
Panel2.Height = heightOldPdos - 65
Dim nameLineB As String = nameLine
Using bmp = New Bitmap(Panel2.Width, Panel2.Height)
Panel2.DrawToBitmap(bmp, New Rectangle(0, 0, bmp.Width, bmp.Height))
Dim bmp2 As New Bitmap(bmp.Width * 3, bmp.Height * 3)
Dim gr As Graphics = Graphics.FromImage(bmp2)
gr.DrawImage(bmp, New Rectangle(0, 0, bmp2.Width, bmp2.Height))
bmp2.Save("C:\TEMP\" & nameLineB & ".png")
End Using
Panel2.Width = widthOldPdos
Panel2.Height = heightOldPdos
Panel1.Width = widthOldPuno
End Function
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Dim seconds As Integer
Label1.Text = seconds + 1
If Label1.Text = "5" Then
Timer1.Stop()
End If
End Sub