Lost document in Microsoft Word on iPad - using Auto-save, doc saved in Files app

Battery on my iPad went out last night unexpectedly, and 6 days of work are gone. When I open the document I was working on, it has reverted to a previous version. I had the document saved in Files, and was using Auto-save. The document is not in any place I would expect to look: not in recently deleted documents, not in OneDrive (naturally, since I was using Files on the iPad).

Where else might I look for this document that represents hours of hard work!? I’ve been using an iPad with Word for over 10 years, and have never had this issue before.