I am running LibreOffice 7.2.4.1 on an iMac with MacOS 11.6.1 and can’t get gridlines to show in Calc. I have done both the Preferences/LibreOffice Calc/View/Visual Aids/Gridlines/Show and Show on colored cells neither of which cause gridlines to show up. What am I not doing?
Maybe your cells actually have borders, and they are explicitly white? Because Calc only shows gridlines where the cells do not have own borders.
Restore the factory state.
Use styles/cell styles for the cell border, if possible.
Cell Styles in Calc
Alternatively, use AutoFormat styles.
AutoFormat Table Styles
Good success!
Try Menu / View / View Grid Lines.
And if do you need to toggle the visibility of grid points: menu View - Grid and Helplines - Display Grid.
Here’s what worked:
Select all cells, Menu/Format/Cells/Line Arrangement, select Preset with all cells lined and change Line Color to Black.