Line Chart drill down not working despite having data

In this example, when I drill filter to show only weekend values, it should ideally show me the orange line data alone, but since green line data isn't available for weekends, it's not showing me any data at all! i.e. when I filter for weekends, I see a blank and empty chart with no x axis values and no line or dot whatsoever.

But I know the orange line data should appear as there is data in there!

Please offer any insights on why this is happening and how to resolve it.