API calls failure with 403 Error code: You have been blocked

When using API calls to gpt-4 in production settings, we started encountering error: “Request failed with status code 403”

Sorry, you have been blocked
You are unable to access api.openai.com

Why have I been blocked?
This website is using a security service to protect itself from online attacks. The action you just performed triggered the security solution. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data.

What can I do to resolve this?
You can email the site owner to let them know you were blocked. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page.

\x3C!-- /.section →
Cloudflare Ray ID: … • Your IP: Click to reveal … • Performance & security by Cloudflare

Have anybody else encountered the problem, and what could be the reason?

You can tracert to api.openai.com and see how far you get. It may be no farther than a few local hops where you can pick up the phone and ask who’s messing with your connection.