I've been using Snapshot successfully for a while now, both to do full and db only backups.
[ I've had this problem recently but I don't think it's relevant here https://premium.wpmudev.org/forums/topic/snapshot-manifest-file-missing ]
I looked at my snapshot dashboard today and the All Snapshots list was empty.
Looking back, the last daily backup was created on 11November. I'm using Snapshot v2.5 and I've granted support access.
In the meantime I've created some new backup profiles, so you'll see those if you log in.