Android: unable to swipe in code editor

I'm taking the AP Computer Science Principles course, using the Android app. Part of the lessons include viewing and editing code in boxes embedded into the lessons. In these boxes, I'm unable to swipe up or down to see the lines above (or below) what is currently displayed. For example, if there are 30 lines of code and the box is only currently displaying lines 6-25, I'm unable to view lines 1-5 or 26-30, even when the lesson suggests I edit or add code on these lines. I've tried swiping on every part of the box, as well as zooming in and out, with no success.

Any ideas? Thank you in advance.