AI Agent returns empty result for Excel file

I’m testing an Appian AI Agent that needs to read data from an XLSX document. I have two copies of the exact same XLSX file stored in two different folders in Appian.

• When I point the AI Agent to the file in Folder A, it works as expected and can read/extract the data.
• When I point it to the identical file in Folder B, it does not work (the agent appears to find nothing in the file / doesn’t extract data).

Both documents are valid Appian documents of type .xlsx, AI Agent uses Semantic Search to read the data, and the file contents are identical. The only difference is the folder they’re stored in. 

Has anyone seen this behavior before or can suggest what to check? Any guidance on why the same file would work in one folder but not another would be appreciated. 

I created new folders, checked the folder security, but I can't find the issue.