Call graph not rendering

Hi, Since a couple of days : https://www.recursionvisualizer.com/ -> message "Rendering call graph..." and nothing is shown. even locally 127.0.0.1/... -> message "Rendering call graph..." and nothing is shown. even after several minutes, whaterver example is used. be on linux/windows/firefox/chrome -> nothing's shown. Thanks for this great tool, very usefull for teaching and understanding. Regards.