Netbackup Tape drive path go down as 2 policies are activated from same NDMP client

Hi,

We have a ploblem of IBM Tape drive path ( from netbackup side) go down when 2 policies activated from same NDMP client. We use NetApp filer as NDMP clients and tape drives are directly zoned to NetApp filers and using 3-way NDMP backups. Recently upgraded to Windows 2012 R2 and Netbackup 7.6.0.4.

Any help appreciated.