Based on the Cloud SWG portal configurations, the Cloud SWG proxy would add either the Original Source IP or an Anonymous IPv6 address as the X-Forwarded-For (XFF) header value to all outbound web requests.
Some website access might break due to this additional HTTP header injected by Cloud SWG.
Cloud SWG (WSS - Web Security Service)
The X-Forwarded-For (XFF) header can be disabled from the Management Center policy (UPE). The following CPL policy can be used for removing the X-Forwarded-For (XFF) header.
define action delete_xff
define condition remove_XFF
Note: Replace example.com with the domain that you want the XFF to be deleted.