Mobile Devices, that have not reported SMM agent inventory recently, disappear from all collections including "All Systems". Upon the next open of the SMM agent and successful inventory report, the missing device reappears in the console.
The Symantec Mobile Management device agent collects specific hardware inventory that updates and renews the Configuration Manager DDR record. If this inventory and record become stale due to device hardware inventory not being reported, Configuration Manager clean-up processes may remove these device objects from the console making them disappear from all collections. The mobile device inventory should still exist in the Athena database but the corresponding CM DDR record that allows the device to appear is gone.
This issue may be seen more often in an environment where the Apple App Store build of the Symantec Mobile Management iOS agent is deployed. This build of agent does not perform background processing for inventory unless it is opened and/or brought to the foreground on the device.
This issue may also be seen in an environment with less-than-desirable network conditions between device and endpoint server. Network conditions may prevent the device agent from reporting inventory before the Configuration Manager DDR purge window is exceeded.
For more information about these Configuration Manager clean-up/purge tasks, please see the following Microsoft Knowledge Base articles:
As a workaround, Symantec Support recommends the following actions to reduce the occurrence of this issue:
Symantec is investigating this issue for other possible solutions and may resolve this in a future release.
Microsoft Configuration Manager 2007
Symantec Mobile Management for Configuration Manager 7.x