Microsoft Word now deletes some documents on Save
(microsoft.com)
Users may encounter an issue in version 2409 where their file is deleted after save if the title contains a capitalized file extension (.DOCX, .RTF) or #. The issue occurs after making an edit to the file and saving when prompted after trying to close Word.
Users may encounter an issue in version 2409 where their file is deleted after save if the title contains a capitalized file extension (.DOCX, .RTF) or #. The issue occurs after making an edit to the file and saving when prompted after trying to close Word.