Best content but cant use

Nothing against Khan academy, just want raise awareness that the app has serious bugs for K to 6 users. After installation, under math there will be primary grade content. After restarting the app, all those content just mysteriously disappears. And, when trying to search for the content, for example, search "3rd grade", it will return "3rd grade math warm up". You try to select, the app crashes.

The website seems to acknowledge this bug but the solution is to "not use the app"!?

Please fix this soon! I will adjust my rating accordingly.

FlyingFiddle about Khan Academy, v3.1.3