In LibreCalc I draw arrows to direct a graphed function to either the primary or secondary axis or to direct a label to a particular line in a graph. These arrows do not get saved properly. When reopening the saved file, the arrows don’t have heads and are not the same length or in the same location. I cannot find any method to save their position. Anchor is discussed in the Help, but does not appear when adding an object inside a graph window.
Always save in native format, .ODS.
Foreign formats don’t always support LibreOffice functionality as the warning says.