Newly created Linux Consumption Function Apps stuck "Service Unavailable" (503) despite state=Running

Question

Hello,

Summary

Every Linux Consumption Plan Function App I create in a specific subscription becomes permanently unreachable ("The service is unavailable.", HTTP 503) on both the main site URL and the SCM/Kudu endpoint, even though the control plane (az functionapp show) reports state: Running the entire time. This has now happened identically three times in two different regions, so it doesn't look like a one-off provisioning glitch.

Environment

Subscription: Pay-as-you-go (Basic support plan) Function Apps: Linux, Consumption (Y1) plan, Node.js runtime 24, Functions v4 CLI: az (latest), Windows PowerShell

What I tried, in order

Attempt 1 — func-app-1 (West US 2) Created successfully (state: Running). Main URL and https://<app>.scm.azurewebsites.net both returned "The service is unavailable." for over an hour. Manual az functionapp restart did not help. Deleted after ~1 hour with no change.

Attempt 2 — func-app-2 (West US 2, fresh name + fresh instance) Same symptom immediately after creation. Confirmed via the Portal's built-in Diagnose and solve problems → Function App Down or Reporting Errors → "Functions that are not triggering" detector:

Host Runtime instance (Consumption Plan) was unavailable for a sustained time period (> 15 minutes) Function was running on 0 worker instance for more than 1420 minutes

az functionapp restart did not resolve it. az functionapp deploy --type zip failed immediately with:

An error occurred during deployment. Status Code: 503, Details: The service is unavailable.

— failing at the SCM connection stage, before any file transfer. Deleted this app and its auto-created App Service Plan.

Attempt 3 — func-app-3 (East US 2, different region, fresh App Service Plan, fresh Storage Account in the same region as the Function App) Same symptom again: state: Running, but main URL and SCM endpoint both return "Service unavailable." from the moment of creation, persisting overnight (checked again ~18 hours later — no self-healing). Zip deploy fails the same way as Attempt 2.

Other checks performed

az appservice plan list — the underlying Consumption plan shows ProvisioningState: Succeeded, Status: Ready in all cases. Resource providers Microsoft.Web, Microsoft.Storage, Microsoft.OperationalInsights are all registered. Azure Service Health → Service Issues: no active incidents reported for this subscription/region at any point. Region West Europe is blocked for new resources on this subscription ("not accepting new customers"), which suggests this subscription may have some kind of restriction/flag — possibly related, possibly not. Storage account co-located in the same region as the Function App (ruled out cross-region storage latency as the cause).

Question

Is there a known issue where newly created Function Apps on a subscription can get stuck with a healthy control-plane state but a completely unreachable data-plane (site + SCM both down)? Is there a subscription-level flag or backend allocation issue that could cause this consistently across regions? Any pointers on further self-service diagnostics, or confirmation that this needs a support ticket, would be much appreciated.