Azure Static Web Apps edge stops responding to all requests for my custom domain (*.quantito.app); other domains on the same edge work

Since about 2026-10-11 14:00 UTC, the Azure Static Web Apps edge no longer answers any request for hostnames under my domain quantito.app. The TCP connection is accepted on ports 80 and 443, but no TLS handshake or HTTP response ever comes back, and the client eventually times out. Before that time, the custom domain worked normally: it validated, its certificate was issued, and it served the site.

What I've checked

• The apps themselves are healthy on their default hostnames:
  • https://kind-cliff-0f7471b0f.5.azurestaticapps.net (Standard plan, the app)
    • https://delightful-island-0806d0d0f.2.azurestaticapps.net (Free plan, the landing page)
    • I sent requests straight to the same edge IP with different hostnames. journal.quantito.app and www.quantito.app hang. Unrelated hostnames on other domains (including other .app domains), and quantito.com, get an immediate 404 from that same edge. So the edge is dropping requests based on the quantito.app hostname, not on my DNS or my network. I saw the same behavior on two different edge IPs and from more than one network:

          curl -v --connect-to journal.quantito.app:443:<edge-ip>:443 https://journal.quantito.app/       # hangs
    

curl -v --connect-to example-other.app:443:<edge-ip>:443 https://example-other.app/ # immediate 404 ```

  - DNS is correct: Cloudflare DNS-only (not proxied) CNAMEs point to the default hostnames above. I also removed the custom domain from the app and added it again. The domain shows "Ready" in the portal, but requests still hang.
  
  - Both apps are affected (two separate SWA resources, two plans), so the cause seems to be the domain rather than either app's configuration.
  

Domain reputation

The domain was registered in October 2026 for a free trading-journal web app (record keeping only, not a broker, no payments). Sign-in uses only SWA's built-in authentication with Google, Microsoft and GitHub, so we never see or collect credentials.

• Verified in Google Search Console, which reports no security issues, and in Bing Webmaster Tools
• Clean on Google Safe Browsing and VirusTotal
• Not on Cisco Talos block lists (a reputation re-evaluation is pending there)
• No Microsoft Edge SmartScreen warning
• SPF and DMARC records, plus /.well-known/security.txt and /.well-known/microsoft-identity-association.json

I checked every subscription I can access: no Static Web App, Front Door, CDN or App Service has any binding for quantito.app. Both affected SWAs currently have no custom domains at all. Even so, the edge still hangs for journal.quantito.app and [www.quantito.app] (TCP connects in ~50 ms, then no TLS/HTTP response, on ports 443 and 80, on edges 20.106.1.90 and 20.98.190.171, tested 2026-10-11 17:22 UTC). An unbound domain on the same IPs, quantito.com, returns an immediate 404. Since an unbound domain normally gets a 404, this looks like a domain-level enforcement on the edge rather than a stale binding.

A control test on 2026-10-11 ~18:12 UTC: I bound a brand-new domain to a new Free Static Web App in a new resource group. It validated, received a certificate and served normally through the same edge IP (13.86.4.76) where journal.quantito.app times out. This points to a block scoped to the quantito.app domain, not to the edge in general.

Questions

1. Has quantito.app been flagged by an automated abuse or phishing system on the Azure Front Door / Static Web Apps edge? If so, how do I request a review?
2. If not, what else would make the edge silently drop every request for one domain?

I'm on a Visual Studio (MSDN) subscription, which can't open technical support requests. I'd be grateful if this could be escalated, and I can share subscription and resource IDs privately