No proper scrolling then reading

Then I`m reading my text I used to scroll pressing Page Down button.
But now text scrolls more than a page.
I think the cause is new bars - in the top and in the bottom of the text area.
The bars appeared, but the scroll algorithm remained the same.

@sdom - You’re right - we’re looking at making some additional updates to the lesson page that should hopefully see the page down button work properly again!