Value in cell is of the form:
=‘file:///Users/xxx/Documents/foo.ods’#$‘Sheet1’.A1
If I change the value in foo.ods, Sheet1, cell A1, then the cell does not update. If I save the file, it doesn’t update. There is an answer from 2015, but there is apparently no longer a ‘Cell contents’ option on the Tool menu which the answer mentions. F9 or Ctr-Shift-F9 was keyboard shortcut apparently - isn’t any more.
F9 (on a cell or when automatic recalculation is disabled) or Shift+Ctrl+F9 recalculate formulas with the current spreadsheet data, including cached values from external sources. They do not (and did not) reload data from external sources. To update external data go to Edit → Links to External Files…, select the data source(s) you want to update and click Update.