When setting up Azure Functions "Always On", HTTP status code 401.

[NagitoTerada]

Please provide us with the following information:

This issue is for a: (mark with an x)

- [x] bug report -> please search issues before submitting
- [ ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

Minimal steps to reproduce

#function_app.py
import azure.functions as func
from fastapi import FastAPI


fast_app = FastAPI()
app = func.AsgiFunctionApp(app=fast_app, http_auth_level=func.AuthLevel.FUNCTION)

1. In the Azure portal, search for and select App Services, and then select your app. In the app's left menu, select Configuration > General settings.
2. I enable Always On.

• https://learn.microsoft.com/en-us/azure/app-service/configure-common?tabs=portal#configure-general-settings

Any log messages given by the failure

2024-04-04T05:58:14Z [Verbose] Request successfully matched the route with name 'http_app_func' and template '/{*route}'
2024-04-04T05:58:14Z [Information] Executing StatusCodeResult, setting HTTP status code 401

Expected/desired behavior

Expected: HTTP status code 200.

OS and Version?

Windows 7, 8 or 10. Linux (which distribution). macOS (Yosemite? El Capitan? Sierra?)

Linux (App Service Plan Premium v3 P1V3)

Versions

• Python: 3.10.x
• Runtime version: 4.31.1.1

Mention any other details that might be useful