Neither of these two functions seem to correctly import into LibreOffice 188.8.131.52 (x64). When I open the downloaded .ods (or .xlsx) sheet, the formulas show up as lowercase (so e.g. “ifs(…)” instead of “IFS(…)”) and only display a #NAME value.
When I replace the lowercase function names with their uppercase counterparts the formulas do work just fine.
I’m not sure if this is a bug with LibreOffice or Google Sheets, as when I unpack the .ods file and take a look at the included content.xml file, the “table:formula=” property also contains lowercase ifs() and concat() values, but an uppercase IF(), which works just fine in an exported file.
Taking a look at the .xlsx file however, after unpacking it and opening the included sheet1.xml file, the “< f>” tag value contains uppercase IFS(…) and CONCAT(…) values. But it’s still not working when I open the .xlsx file in LibreOffice, the formulas are still displaying as lowercase and the value as #NAME.