The FortiGate is acting as an upstream reverse proxy, so FortiWeb sees the FortiGate address as the direct source IP unless it is configured to read the original client IP from the inserted HTTP header. Since FortiGate already inserts X-Forwarded-For, the proper fix is to modify the FortiWeb protection profile or related client-IP configuration so FortiWeb uses that header for client IP detection. This restores accurate logging, rate limiting, reputation checks, and IP-based enforcement. Changing to one-arm proxy is unnecessary and disruptive. Disabling IP-based detection weakens protection instead of fixing attribution. Recreating the policy with a predefined profile does not address the missing client IP mapping. The correct adjustment is to trust and use X-Forwarded-For.