As per the description above, you are getting a garbled Excel or Word after conversion, Is that correct?
Please refer to the following KB doc which discusses the similar issue Text is garbled in converted file | ExportPDF
Try exporting the PDF file through the URL https://cloud.acrobat.com/exportpdf with your Adobe ID and password on a browser like Chrome, or Firefox, or Safari and see if this brings any difference.
Have you tried exporting a non-scanned PDF file? Try exporting any other PDF file.
Let us know how it goes and share your findings.
If the issue is specific to one PDF file, is it possible to share the PDF file with us so that we can check at our end?
To share the PDF file, please use Adobe Send feature, share the link to PDF via private message only How Do I Send Private Message Link: https://forums.adobe.com/thread/1184148 as we have not received any attachment in your previous response.
Also, refer to the KB Text is garbled in converted file | ExportPDF
There are many PDF files that I want to convert and I did not have any problem before!
Also, I'm not sure how to send a secured private message with attachment as mentioned below.
Please contact the PDF producer, or if possible share the source file, as it seems to be a font issue in the current scanned PDF.