A Microsoft file hosting and synchronization service.
Hi Laurence,
To check the version history of a file in OneDrive, right-click the file (either on the web or in File Explorer) and choose "Version history." You may be able to restore the right version from there.
Try to check One Drive recycle bin as well. Older versions that was marked were deleted or moved to the recycle bin. Check if the version history if it can still show the last version you were working on.
I have also linked a non MS website here as they have workarounds:
https://www.reddit.com/r/onedrive/comments/1g1dy3w/onedrive_overwriting_files_with_older_versions/
Hope it helps.
All the best,
Restee M.