There are some bugs regarding Windows and in-use files when creating backups (fixed in the next release afaik).
I’d suggest checking to see which backups are weirdly small and see if you can find one that has the changes you made.
You can also use something like MCA Selector to grab chunks from one world folder and copy them to another, in the event that one backup doesn’t have everything and you need to “stitch” things back together.