Filemaker has a limitation when ik comes to detecting is a field has text that doesn't fit on one page. It cuts of the remaining text. You could set the size of the main part lager than the page, so it creates a second page. Drawback is that if the text is smaller than the field, you always gat a second, empty, page.
I've seen solutions where a script resizes the text itself to fit into the field, but then you get inconsistent prints which different font sizes.
Is there a script option to resize the main part of the layout and the the textfield depending on the length of the text? You could trigger such script when entering the record or printing the record and depending on the length of the text, the main part would be larger, so the text flows over two pages or stick to one page.