Ok, so a few things.. How are you doing your snapvaults, are you having DFM protection manager control your policies, or are you doing them directly from the command line.
As per the snapvault best practice guide, all destination snaps should be disabled, snap sched volname 0
Snapvaults should be controlling when the snapshot gets taken, that's how it works.
so for example, a snapvault that is controled from DFM initiates a snapvault transfer and then takes an preserves a snapshot based on the policy you set.
If you aren't using DFM, then it's done from the CLI with retention policy. The whole point of snapvault is that it replicates data and then takes a snapshot... volume snapshots on the destination via snap sched are not a good idea.