Check both records are in place
The DNS table shows an A record and at least one TXT verification record. Both must be added. A common mistake is adding only the A record and skipping the TXT. Go back to Connect → Deploy, copy the TXT record values, and add them at your registrar.
Common causes
DNS has not propagated yet — wait 15 to 30 minutes and click Refresh.
A conflicting A or ALIAS record on the same host is overriding yours. Remove all other A records on that host — only one should point to 216.150.1.1.
You added the record to the wrong host — for a root domain it should be @, for a subdomain just the subdomain part (e.g. quote, not quote.yourbrand.com).
Cloudflare proxy is on. If your DNS is on Cloudflare and the A record is set to Proxied (orange cloud), switch it to DNS only (grey cloud). The proxy intercepts traffic in a way that breaks verification.
A CAA record is blocking SSL issuance. Remove it or add an entry that permits the certificate authority Vercel uses.
Verify from the command line
Run dig A your-domain.com +short in a terminal (or nslookup your-domain.com on Windows). You should see 216.150.1.1. If you see a different IP or nothing at all, DNS has not propagated or a conflicting record is winning.