I am running into the same issue - but only on export. I am using the Visualize.js library with AngularJS on the front end. Report renders fine - no breaks, but on export, the XLS renders in multiple segments. Pagination is set to false on the JasperServer. I tried adding the option: "pagination: false" to the export call, but it seems to be completely ignoring the parameter when it makes the actual REST call. My requested export format is there, and if I specify number of pages I can see that too, but pagination: false is never there.
Is this a known bug with the Visualize.js library?