I have a problem with page layout of my score. The document was formatted as Marching Band when created using the document set up window, so parts are octavo size/landscape orientation.  I added a measure stack of 8 measures to the end of the score, which added two pages.  However, the pages are half pages on the screen so the bottom half of the page is greyed out.  How do I make these full pages?

I am using Windows 10, Version 25.

Thanks for your help!