Finally, after some waiting and communication, the customer support team revealed the issue:
OpenAI detected that a portion of our traffic (likely ~5%) from our Cloudflare Worker app originated from China, Hong Kong, and Macau before June 2, 2024.
Lessons learned: If you plan to use OpenAI’s API key in Cloudflare Worker or other edge computing products, make sure to whitelist traffic only from regions supported by OpenAI. You can find the supported countries here: OpenAI Supported Countries.
Overall, we have had great experiences interacting with OpenAI in the past, but this time, the customer support was lacking. It seemed like they intentionally avoided revealing that they were blocking traffic from China and other regions. If I hadn’t been persistent in my inquiries, I wouldn’t have known the exact issue.
As of now, we are still uncertain if this case is resolved. Customer support hasn’t confirmed if we are still receiving traffic from non-supported countries. We are left to guess and wait.
I hope OpenAI improves its customer support in the future.