Text boxes used to get bigger as you wrote more in them. Now they've changed so that they stay the same (small) size and a scroll bar appears on the left. This is annoying. But you can change the size of it by click and dragging the bottom right hand side of the text box to make it much bigger.
I don't know why they made this change, it won't be obvious to people that they can click and drag and it used to resize automatically, why change that?