> I had used an iCloud Hide My Email address for the purchase so a day later I get another email from NoFraud
I got hit by a merchant using "NoFraud" as well. After making an order from the merchant's site, using Apple Pay on the web (which is, allegedly, rather hard to fake), I received an email saying my order was canceled as it "appears that a merchant-specific email address was used" and to "please resubmit the order using your personal contact details".
They were right, because I always use [merchantname]@subdomain.mydomain.com. Whatever it was couldn't have been that important because I didn't bother redoing it if they're going to be that picky.
(I can't find the purchase confirmation and subsequent email in my email, probably because I deleted it out of annoyance, so I'm not naming who I think I remember it being just in case I'm wrong)