Do I need to run a VBA command like a Refresh or Requery or Repaint or
something like that to make the charts appear without having to close
and re-open the workbook?

same thing happens to my 2 linked xlsx workbooks.... (1 for chart & 1 for data).
It's like two opposite hands, one is "close" for the other to open-view the chart..
quite intriguing..

:-")