Layout is ignored when exporting to pdf

Hi- I'm having trouble with exporting a file to pdf. I had previously started a project with only piano and decided to add bass as a second instrument. I've used several of the layout features (line break, page break, etc) in the piano version and it came out looking fine when I exported the project to pdf. However, when I export only the bass part, the layout features seem to be completely ignored by musescore. I closed then reopened the project, and then deleted and re-input the line breaks and other features, but when I export, the same thing happens. How do I fix this?