Since Frendrick hasn't responded in 2+ years (and since I'm having exactly the same problem now), I'll chime in and hope for a response.
Here's what my situation looks like, using iTunes to try to restore from a local backup in Windows 10:
The folder named "Backup" contains a number of different backup folders, each with a long alphanumeric name.
One of those (let's call it BackupA) contains approximately 300 files (including two .plist files) with a date of 8/2016. It also contains a Status.plist file dated 9/2017 and one folder named "Snapshot". The Snapshot folder is ~20GB in size and contains 20,000+ files (but no .plist files), all dated 9/2017.
When I use iTunes to restore my new phone [old phone was backed up in 9/2017 but is dead and gone now] from BackupA, it restores (some? but not all?) data from 8/2016 but does not see ANY of the 9/2017 data in the Snapshot folder.
HOURS AND HOURS of time with Senior Technical Support at Apple has gotten me nowhere closer to resolving this. Any thoughts?