#1) - Open SMP Console and make a mouse double click on your software package ⇒ then click on "Package" tab ⇒ click on Package name and then click "Edit" button ⇒ click on "Package Server" tab ⇒ make sure that all required package servers are set for this package, otherwise they will be able to download this package from NS.
#2) - If there is no problems in #1, then check Symantec Management Agent logs on your Package Server to identify root cause of not delivered Package. Probably your remote PS doesn't have access to location where to download this package from.
C:\ProgramData\Symantec\Symantec Agent\Logs\
Have you tried to import a new software package, using UNC Location instead of Software library using? Same result with package downloading by remote PS?
Thanks,
IP.