Managed Functions deployment consistently fails: "Failed to deploy the Azure Functions" (build succeeds, deploy times out during polling)

[TBPsupply]

Describe the bug

Since 29 May 2026, every deployment of our Static Web App fails at the managed
Functions deployment step with:

The Oryx build and artifact upload succeed; the failure happens on the Azure side
during "Polling on deployment". The same /api code deployed successfully on
28 May 2026.

Reproduction

1. Push to the linked branch (or open a PR) — workflow Azure Static Web Apps CI/CD runs.
2. Build + "Zipping/Uploading build artifacts" complete fine.
3. "Finished Upload. Polling on deployment." → Status: InProgress … → Status: Failed.
4. Job ends with "Failed to deploy the Azure Functions."

Log excerpt

Environment

• Static Web App: tbp-dashboard
• Region: West Europe (verify on the resource Overview)
• Plan: Standard (adjust if Free)
• API: managed functions, 5 functions, classic v3 model (function.json + index.js)
• Functions runtime: ~4, Node 20 (pinned via platform.apiRuntime: "node:20")

What we have already ruled out

• No EnvironmentId tag on the resource (Tags blade empty)
• Deployment token valid (upload + polling start succeed)
• No FUNCTIONS_WORKER_RUNTIME app setting
• api_location correct; /api contains valid v3 functions
• Environment variables present and correct
• No Service Health incident in our region
• Forcing a clean function redeploy via a host.json content change did not help
• Reproducible across 6+ re-runs on both preview and production environments

Expected behavior

Managed Functions deploy succeeds as it did on 28 May 2026 with identical /api code.

Additional context

The failure occurs at varying poll times (15s / 45s / 61s) rather than failing fast,
which suggests a backend timeout/flakiness in the managed Functions deployment rather
than a configuration error on our side. Requesting backend investigation.

[slavomirs]

I had the same issue, was mid-way describing my situation here and before hitting send I tried one more run and it finished successfully.