Why does ConfigMgr (SCCM) import drivers selectively?

I am trying to import drivers into ConfigMgr (SCCM). These are meant for creating a driver package for a new laptop model. My problem is that the ConfigMgr (SCCM) is importing only selected but not all drivers. It also produces a message that “Selected driver has already been imported at this site.” Does anyone know why ConfigMgr (SCCM) is selectively importing drivers?
