Which specific course is this in?  Is the difficulty in the articles, exercises, quizzes, or tests?
What device (iPhone, Windows computer, Chromebook, ...) are you using?
Can you share a screenshot of what you see?

When I start an Algebra 1 quiz, I see a dark gray scroll bar on the right that I can drag to show me content that is below the window frame:
~ Janice, KA user