Hi,
First post in Dash Community, and much thanks because this is a great library for graphing and charting! 
Fyi, I have encounter a problem where after a pie chart is being clicked few times, the click event callback might not being fired properly if i need to click the same pie chart portion again, especially after i interact with other components in the same page. The situation is quite inconsistent, sometimes the click event triggered and sometimes not.
Note that the pie chart is plotted in subplots with another bar chart together, so I am not sure whether the issue is reproducible if the pie chart is plotted alone with itself. Also the click event involves a few callbacks including update the pie chart itself.
Any helps will be much appreciated. Thanks.