403 PERMISSION_DENIED - "Your project has been denied access" on multiple fresh projects

Hello,

I’m getting a persistent 403 PERMISSION_DENIED error when calling the Gemini API
(model: gemini-2.5-flash) via REST API (tested with Postman, raw HTTPS request
to generativelanguage.googleapis.com).

Error response:
{
“error”: {
“code”: 403,
“message”: “Your project has been denied access. Please contact support.”,
“status”: “PERMISSION_DENIED”
}
}

Troubleshooting already done:

  • Tried with two different projects, including a completely fresh one created today — same error on both.
  • The Google AI Studio web playground (aistudio.google.com) works perfectly fine with the same Google account — I can chat with models with no issues there.
  • Not using a VPN.
  • Application/API key restrictions are set to default (no IP/referrer restriction).
  • Region: Vietnam

This strongly looks like a false positive from an automated abuse-detection filter on my account, since the web playground works but the REST API key is blocked across all projects under the same account.

Project details:

  1. Project name: DATN, Project ID: datn-4999..
  2. Project name: My First Project, Project ID: project-0714f393-f1ac-4634-895…

Could you please review and restore API access for this account? Happy to provide any additional information needed.

Thank you!