Formatting bugs

I'm trying to create a big band arrangement of "Manteca" for my arranging course in school, but whenever I try to change my formatting from "A4" to "Letter" and switch the orientation from "portrait" to "landscape", the bottom of the score gets cut off and the software no longer fits the score to the new formatting like it did in 3.6. So right now, I'm stuck with the "A4" page size and "portrait" orientation until there's a patch that fixes it. Anyone have a solution to work around it?