Agents are attempting to download packages from package servers in the same site as the NS, or from the NS itself instead of from the package server configured for their site/subnet. This may only be happening for some packages.
In trace and verbose logs, you can see a message '
Download time has exceeded the configured value, using NS Codebases'
The setting in
C:\Programdata\Symantec\SMP\Settings\Coresettings.config file is the fallback value where after an agent has failed to download a package, it will attempt to download it from the Notification Server or a package server in the same site.
MaxAgentDownloadTryingTimeMins is set to 240 minutes and is intended to allow packages to continue to be distributed even in the event of a failed package server.
For environments where this is disruptive or not desirable it can be disabled by setting
MaxAgentDownloadTryingTimeMins to 0 in.