If you are planning to deploy version 5.1.8.122, you must be aware of a critical architectural change introduced in the 5.1.x lineage regarding macOS and Windows updates.
The 5.x series introduced significant changes from the older AnyConnect 4.x lineage: cisco secure client 5.1.8.122 download
Why might an administrator specifically choose version 5.1.8.122 over the absolute latest release? If you are planning to deploy version 5