Dynamic Chart VBA data range issue

Hi, ive used some code from a youtube video ive found and altered it to fit my data range. However, the chart is now calculating all the blank cells beneath it. I'm very new to all this and so not entirely sure what I'm doing. Any help would be greatly appreciated. Here's the code before:

Dim chtobj As ChartObject

 lr = ActiveSheet.Cells(Rows.Count, 1).End(xlUp).Row
Set chtrng = Range("a1:c" & lr)

 Set ChartArea = Range("c" & lr + 3 & ":h" & lr + 15)
 ActiveSheet.Shapes.AddChart2(201, xlColumnClustered).Select
 ActiveChart.SetSourceData Source:=chtrng
 Set chtobj = ActiveChart.Parent

 chtobj.Top = ChartArea.Top
 chtobj.Left = ChartArea.Left
 chtobj.Height = ChartArea.Height
 chtobj.Width = ChartArea.Width
 ActiveChart.ClearToMatchStyle
 ActiveChart.ChartStyle = 209

And this is what I've changed as my data starts in h20, i20 and j20.

Dim chtobj As ChartObject

 lr = ActiveSheet.Cells(Rows.Count, 1).End(xlUp).Row
Set chtrng = Range("h20:j20" & lr)

 Set ChartArea = Range("c" & lr + 3 & ":h" & lr + 15)
 ActiveSheet.Shapes.AddChart2(201, xlColumnClustered).Select
 ActiveChart.SetSourceData Source:=chtrng
 Set chtobj = ActiveChart.Parent

 chtobj.Top = ChartArea.Top
 chtobj.Left = ChartArea.Left
 chtobj.Height = ChartArea.Height
 chtobj.Width = ChartArea.Width
 ActiveChart.ClearToMatchStyle
 ActiveChart.ChartStyle = 209