Test

That is, I *think*, to do with the right-hand ruler settings restricting the width of the text. In the sample file attached, the first paragraph is set to the margins used for a typical A4 page. The second paragraph is set to about half of that. Opened in composition mode, the first paragraph can expand far more than the second one.

To change the margin, (1) press CMD R to show the ruler, (2) put the cursor in the paragraph you want to change, and (3) then reposition the right margin marker as ...