I have a multi-tenant Next.js project (App Router, Turbopack) with three domains configured on the Production environment:

• domain.app (apex) — shows "Valid Configuration"

• www.domain.app — shows "Valid Configuration", 308 → domain.app

• *.domain.app (wildcard, for per-merchant subdomains) — stuck on:

  Proxy Status Unknown Failed to check whether a proxy is in front of this domain. Refresh to try again.

This didn't clear after multiple refreshes, and it also didn't clear after fixing an unrelated apex→www redirect that was previously blocking the apex domain's own check.

What I've already confirmed is actually working, despite the warning:

• Nameservers are correctly on ns1.vercel-dns.com / ns2.vercel-dns.com (used the required nameservers method for wildcard cert issuance via DNS-01).
• An arbitrary/made-up subdomain (e.g. probe-test.domain.app) resolves correctly, serves valid HTTPS with no certificate warning, and gets a correct response from my deployed app (not a Vercel-level error).
• The apex and www domains both check out cleanly once their redirect was fixed, so the deployment itself is healthy and DNS is fully propagated.

My question: is the proxy-check simply unable to complete for wildcard entries because there's no single literal hostname to probe (only *.domain.app as a pattern, not a resolvable address by itself), making this expected/cosmetic for wildcard domains specifically? Or does this indicate a real misconfiguration I should keep digging into?