Missing files in NAS with "Cloud Drive Sync"

[colomailbe]

Dear,

I'm using "Cloud Drive Sync" to replicate ~100Gb with my Google Drive account.
It used to work well since a few months, but I noticed yesterday that some files from 1 week ago were missing in the NAS.
If check the logs of the application, it just says that everything is running fine (there's absolutely no error or warning).

Is there any way to force the application to synchronize those missing files?
- Delete all files on the NAS and do a resync is not an option due to size
- Manual copy of the files to the NAS is not an option as there's thousands directories and subdirectories

OR any workaround or better (more reliable) app?

Thanks!

Colo