403 PERMISSION_DENIED on generateContent even though billing is linked and models endpoint works

Hi, I’m seeing a project-level Gemini API access issue.

Project name: linkedin-buddy-ai-dev

What is already confirmed:

  • Billing is linked to the project
  • My account has Owner access on the project
  • AI Studio shows the project and API key correctly
  • GET /v1beta/models works successfully
  • POST /v1beta/models/gemini-2.5-flash:generateContent returns:

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

Additional symptom:

  • In AI Studio usage / rate limits, I see:
    “Project quota tier unavailable. Please contact your project administrator for assistance.”
  • Usage data fails to load

So the project/key can authenticate and list models, but generation is denied.

Could someone please check whether this project/account is stuck in a broken quota-tier or access state and enable generation access?