Between 12:50 and 13:03 UTC on August 25, new WebSocket connections to stt-rt.eu.soniox.com failed to establish. Existing connections were unaffected throughout.
While enabling Cloudflare load balancing, traffic was routed through a hostname not covered by our Cloudflare certificate, causing TLS handshakes for new connections to fail. We rolled back the change and connections recovered.
Cloudflare's Universal SSL does not cover multi-level subdomains (unknowingly). We're manually provisioning certificate coverage for these hostnames before re-attempting the rollout.