We apologize for the inconvenience caused, as per the description above, the date format in the PDF file is changing to mm/dd/yyyy instead of the format in Excel file dd/mm/yyyy, Is that correct?
The date format should not be changed. Try converting the excel file to PDF using the URL https://cloud.acrobat.com/convertpdf and see if this brings any difference.
If the issue persists, please share the excel file with us using Adobe Send, and share the link via private message so that we can try it at our end. How Do I Send Private Message Link: https://forums.adobe.com/thread/1184148
Let us know how it goes.