This is a known issue with Imperva Cloud WAF and I have a user story/user voice out there which would benefit from upvotes to convince Imperva Cloud WAF dev teams to fix/enhance. Please vote for it.
https://imperva.uservoice.com/forums/957317-cloud-waf/suggestions/48440006-support-for-origin-setting-page-in-cloud-waf-porta
#CloudWAF(formerlyIncapsula)------------------------------
David Osborne
Technical User
GreenSky, LLC
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