How do I display a pie chart in focus mode?

I like to use 'buttons' to save space. This is just when you minimize a graph to the point where you can only see its title surrounded by a border. The user can then 'focus mode' to display the graph.

I am trying to show a pie graph in this fashion but it won't let me. The histograms are absolutely fine, but when I click the button for pie graph (like in the picture) I just get a blank screen.

How do I fix this? I have attached images of attempting to focus mode a pie graph verses a stacked column chart.