How net.sf.jasperreports.export.xls.one.page.per.sheet work ?

Hi,
I do a post recently about xls, I'm doing a report was printed every sales of the company in all year and I need divide the pages in months, the report worked but I don't know how I divide the sheets,  The solution they gave me does not work, I go to propriets of the report, and I put the net.sf.jasperreports.export.xls.one.page.per.sheet like true, I mark the "no pagination" and put a break in a group, every time the field month change the page was supposed to break, but this don't work, I try dismark the "no pagination" but don't change nothing, he make 16 pages, I'm printing just 2 months, it was right to print only two pages.

Anyone knows how this work ? 

this is the last post: https://community.jaspersoft.com/questions/1111626/sheets-xlsx