Charts don't show the right period

For several sites I made weekly reports.

When I download or ask Piwik to send me the report, all is OK.
But if the report is send automaticelly every monday, all charts show a 6 month period. The tables show the right period, the passed week.

Is this a bug or have I bad configured the report ?

Hi @rolles - see: Evolution graphs: buttons to switch the display of historical data by day, week, month or year · Issue #955 · matomo-org/piwik · GitHub