Why is an unwanted referral still showing in GA4 after I add the domain?

Adding a domain to GA4’s unwanted-referral list only affects events GA4 receives after the change, so the old referral can still be sitting in your reports. It also doesn’t block that traffic or delete it; GA4 just ignores that referrer for matching new events. And if someone first arrived through that domain before you added it, GA4’s last-non-direct-click attribution can keep crediting the domain when they later come back directly. Check a date range that starts after the change and look at fresh sessions. If it’s one of your own domains or a checkout flow, make sure cross-domain measurement is set up on both sites with the same Google tag and data stream too—adding it as an unwanted referral alone won’t repair a missing tag or broken cross-domain handoff.