Combo DropDown List is moving after text selection

Hi,

I am new to VBA. I am trying to have suggested name in combobox. After the name selection, it kept moving in all the sheets. Below are the VBA codes.
I added the ComboBox1_Close() to avoide this but still not working. Please refer to attachment.

Private Sub ComboBox1_Change()
ComboBox1.ListFillRange = "DropDwnMemberList"
Me.ComboBox1.DropDown
End Sub

Private Sub ComboBox1_Close()
Me.ComboBox1.DropDown = ""
End Sub

Can anyone assist. Thank you.