I am having trouble restoring a snapshot. It was stuck for

I am having trouble restoring a snapshot.
It was stuck for a long time, and now all the snapshots in "all snapshots" list are gone.
I checked the folder (wp-content/uploads/snapshots) and the files are still there.
Could you please help me restore back to Oct. 20? (all files included) The snapshot file size is 41.5MB. (Support access is turned on.)
----update: I refreshed the folder and all the snapshot files were gone. Thankfully, I had them also saved in dropbox, so I uploaded one to the folder, but it's still not showing up on the list.
I tried changing permissions of the file, reinstalling the plugin, switching to a default theme, and deactivating all other plugins.
Please help, this is urgent. Thank you so much in advance,