There is sometimes missing a period of data from the graph.
It happens when I close Firefox and later reopen it (with the tabs I had before restored).
It seems the page remembered the state from last time and then continued to add new data. So there was a gap in the graph (data from the period when I had Firefox closed).
Selecting different period sizes (M15, M5, M3....) does not load the missing data. Neither does clicking the Reconnect button.
If I refresh/reload the page, then the new graph shows all data. But then I lose the accumulated lines in the "Time & Sales" table...
I believe the page could detect such a condition and reload the graph data by itself.
Thanks for the great page, by the way!