When printing a spread sheet to a printer a blank sheet is put out by printer. When printing to PDF it produces a blank page.
And, can you attach a sample file, which produces such result? The crystal ball, it's not available. :) Please paste here the information on Menu/Help/About LibreOffice (There is an icon to copy)
You have not well-defined the height for 'Header' and 'Footer' on the page style. There are 15.9 cm of height for both, so no place to print the spreadsheet data. For this kind of question, please look for help in ask.libreoffice.org