What is impact of Database Vault impact on AUDIT_TRAIL

12.1.2.7

Linux x86-64

Oracle Linux 6

Audit Vault (12.1.2.7.0) and Database Vault enabled

This questions has a few angles to it, any help or insight would be greatly appreciated:

There's a database user that will be used to remotely access the AUDIT_TRAIL and CHECKPOINT tables. 

As AVSYS, SELECT obj priv on these tables was granted to the remote access user. 

The remote access user can query the CHECKPOINT table and get the correct results, data and # or rows.

When the remote access user attempts to query the AUDIT_TRAIL table, it gets "no rows", even though there are several dozen audit trails.