SEP (Symantec Endpoint Protection) for Mac cannot scan folders that are protected by "Privacy Preferences Policy". For example, a macOS user's calendar or address book.
SEP for Mac
Generally this type of access is provided to an application by configuring macOS Privacy Preferences Policy.
References: Prepare your institution for iOS 12 or macOS Mojave - last paragraph: "You can allow apps to access certain files used for system administration, and to allow access to application data..."
But at this time, SEP for Mac does not support macOS Privacy Preferences Policy settings.