In the summary of a dynamic group by in a grid the graph is not updated

Hi,
as mentioned in the title i have a dynamic group by on a field of a grid. In the summary a i see a graph and the table of data.
But if i change , inside the summary, the group by type or i change the order by on a column the table of data change correctly but not the graph that remains the initial one.

What to do ?
Gianpaolo