I have not changed anything from the example i copied from the Flexdash, and it is having in string form and it is working. i changed that to an array and it still is working.
the same inject node i copied with just changing the number of data points to suit my msg,payload and it is not working even in string mode or an array mode.
i will try to get my data to have 7 series to match your example and just change the msg.payload and see.