We ran into this same issue. Jobs that only depicted a Job ID. VSupport recommended the following, and it fixed the issue:
Bring NBU down on the master.
Go into the following directories and delete all the files:
Unix:
/usr/openv/netbackup/bin/bsched.d
/usr/openv/netbackup/bin/bprd.d
Windows:
\<install_path>\veritas\netbackup\bin\bpsched.d
\<install_path>\veritas\netbackup\bin\bprd.d
Restart NBU on the master server.
Those phanton jobs should be gone from the activity monitor.
Thanks,
Bob