1. Közösség
2. Mobile Platform Questions and Feedback
3. Allow video download to external SD cards

If you are able to root your android device you can use the app link2sd to move the khanacademy app to your sd card. It costs a buck or two but works great and with any app.

1. Közösség
2. Mobile Platform Questions and Feedback
3. Android App navigation (Galaxy Tab S6)

It's the same for me on my tablets (S2 +S3). This seems to be an issue with the tablet UI the devs hopefully are aware of.