Possibly you have disabled displaying zero values in OptionsLibreOffice CalcView. This option does hide those values on screen - but does not affect printing - this is just a visual aid.
To properly hide zero values, one way is to use a proper format string. Preferably in corresponding cell style; or just simply for selected cells, using menu FormatCells, Numbers tab. You may use something like this (of course, tuned to use your locale's decimal/thousand separators and required number of digits): 0,00;-0,00; - nothing after the second semicolon tells that the zero values are to not be displayed.