PageSpeed giving ERR_CONNECTION_FAILED Only on production

问题

We have our development page giving correct score on page speed insights.

https://developers.google.com/speed/pagespeed/insights/?hl=en&url=https%3A%2F%2Fdev.techtitute.com

But our production page always returns scan error:

Lighthouse returned error: FAILED_DOCUMENT_REQUEST. Lighthouse was unable to reliably load the page you requested. Make sure you are testing the correct URL and that the server is properly responding to all requests. (Details: net::ERR_CONNECTION_FAILED)

https://developers.google.com/speed/pagespeed/insights/?hl=en&url=https%3A%2F%2Fwww.techtitute.com

The strange thing is that web.dev (which also uses Lighthouse under the hoods) is giving correct score for both pages, also gtmetrix, pingdom and Chrome dev tools Lighthouse tab.

Both pages have the exact same code, both are running on windows Azure App Service. The only differences are:

On production we are injecting Google Tag Manager scripts with analytics, fb pixel, linkedin and others. Also we have an azure traffic manager to distribute traffic based on geolocalization of the user (Europe or Latam).

What would you think could be the problem of production page giving that error?

UPDATE 09/07/2020

We have created a parallel environment of traffic manager geographically distributed pointing to 2 app services with the same code as production, but with another domain: dev3.techtitute.com. Now page speed is giving the same error on this subdomain, as the production one. So we think it's related to azure traffic manager configuration.