the problem is that you tell the table calculation to make use of "Quarter of Invoice Date". Once you toggle between different times, let's say to "Month of Invoice Date", then "Quarter of Invoice Date" disappears and the table calc becomes invalid. When you uncheck that box in all table calcs toggling works. With your example data the data does not change but I do not know if that's the case with your real data.
About the turning the dots into a continuous line: you need more data points. Right now your Qty*Price(runSum) is broken out by Description where you got only one data point for each description over time.
Does this help?