If the client source IP address is required for audit logging, configure your load balancer so that it passes the requests through with the original requesting IP address.

Enable the load balancer to insert X-Forwarded-For for each request and then configure Audit to log the X-Forwarded-For header (Configuration > Audit > Header Name 1 = "X-Forwarded-For").

See "audit protocol header" in the StorageGRID Administration Guide.