Good question! As you’ve discovered, each organization of the data results in a different number of points in the two graphs. And only one organization at a time is possible. So, it is not possible to produce both a graph with 12 month points and a graph with 24 hour points at the same time.
A workaround which you may already have discovered is to click on the graph’s camera icon and open the image in the draw tool where it will be displayed statically, not changing when you restructure the data. (Of course you forgo dynamic selection for the static image.)
Bill