Downloaded XLS file malfunctioning in Calc

Weekly I download a worksheet from my account, it is in xls format.
When I open it either in LibreOffice calc or in Microsoft Office Excell and try to sum a column of numbers, it does not even draw a rectangle arond the cells to sum.
Entering manually into the sum formula the first cell and the last cell (=sum(d4:d15)) it gives zero or something else except the sum.
Now I define (for the test) another column as numbers, enter manually the figures from each cell into the new column, when finished click on sum, and it works (only on this new column).
From anothe account I download a xlsx file, open it in LibreOffice or Excell, sum works fine.
Is there some problem with this xls format ? Or, how to make it work ?
LibreOffice is updated to 6.0.5, checked also in previous version 6.0.4 - the same.
Answers will be appreciated

Thank you for the sample file you provided so that we can easily see if “this xls format” has some problem or not.

Given that XLS was the default format for MS Excel for very long time, and that your file does not work properly in Excel, it seems likely that the problem is not in format itself, but in the file. Of course, it helps to know what “account” from which you download means - i.e., what is generating the file. Isn’t it Google Docs by chance, that is notorious for broken files?

@Motim - Just to add to Mike’s helpful comment: we really need to know the source of the download (which seems to be where the issue arises) to offer meaningful help. Thanks!