Collection hostname is pending or invalid

Compare the full collection hostname in Sites → Settings → Collection domain with your authoritative DNS record. It needs one CNAME to the displayed target.

DNS or TLS remains pending

Remove conflicting records for that name, confirm you edited the active DNS zone and allow propagation time. Certificate issuance follows DNS validation; keep the CNAME in place while it completes.

Hostname is active but tracking fails

Publish the updated site snippet, check the allowed page origin, and run Validate. A successful /health response alone does not prove that the hostname maps to the correct site or that event delivery works.

Advertising URLs should open your landing page directly. They should not use the collection hostname as their destination.

Remove a hostname from site settings before reusing it elsewhere, and republish the default collector snippet on the site.