When an Insightly administrator adds a new user, an Insightly contact is created for that user. But system users have special contact records.
When we look at one of these contacts, there's a red icon with a "SYSTEM USER" label above their name.
These contacts can only be deleted by Insightly administrators when the user is deleted from the System Settings page, and they cannot be cloned or merged into other contact records.
If you are syncing contacts to Google, these system users will not sync because they already exist in your G Suite contacts directory.