Hi David,
Thanks for sharing your experience with us.
To troubleshoot the issue, we'd like to confirm the following information:
1.Regardign Get Data>From File>From SharePoint Folder, after you type the SharePoint
folder's site collection URL and click OK, which option do you choose next?
Anonymous/Windows/Microsoft account?
2.For "Most files are returned however some are missing (the list is incomplete), specifically some that I have recently uploaded to the sharepoint site and can see are present in the browser. "
Please provide some related screenshots.
3.Regarding "I have tested this process on another sharepoint site and it looks to work without problem. "
It seems that the issue only happens to this specific site.
Please create a new document library, then check the result.
4.Detailed Office version.
Please go to File>Account> then capture a screenshot of Product Information as below:
Regards,
Tina
[Updated by Tina Chen MSFT, September 14th, 9:32AM (UTC)]