Change the visible status for row of Datagridview (VB.net)

I try to implement collapse/expand rows by change the "visible" status.

1. For i As Integer = startIndex To endIndex ' collapse 
            Me.dgv.Rows(i).Visible = false
Next

2. For i As Integer = startIndex To endIndex ' expand
            Me.dgv.Rows(i).Visible = true
Next

The rows are showed normally. 

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But after collapse once, I try to expand it. But there are a few only one line showed normally.

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What causes the issue? Do I need to set any properties for this?

Any clues?

Thanks