Charts not visible

Hi,

I'm a beginner of WpA. I created a demo tenant with Contoso - WPA Public Demo. It works fine except when I try to see any charts, they are not visible, and it says there is a problem loading chart for this section. For eg. if I Goto Home > Enhance Organizational Resiliency> See Your Insights>Explore the stats, I can't see the chart. Can someone please help.