We have a status called 'QA Done' and another called 'Done'. Both have their status to be 'resolved' but only 'Done' seems to count towards the burn-down chart.
I have noticed one thing. The columns in the board settings are slightly different. Do you see how the bar is blue for the 'QA Done' column but not for the 'Done' column? When I moved the 'QA Done' status into the 'Done' column, it registered in the burn-down chart! So I guess if I can get the 'QA Done' column to also have that green line? Not sure if that's possible - I can't see that as an option.
