in principle it should work to place XLSX files from MS Excel.
Did you test with some plain data where no formulas are present in the file?
What is the creator app and creator version of the XLSX files?
Were these files actually created by Excel or some other source?
Thank you for your answers. This was a file downloaded from Google Sheets… Maybe that's why… But once this file has been converted to xls, it works well. I'll try with a "normal" xlsx and I'll let you know.
OK it seems to be a problem with files from Google Sheets, for with a "normal" xslx I just created for test, it does work normally.