API_KEY_SERVICE_BLOCKED on generativelanguage.googleapis.com — 100% error rate, all checks pass

Project number: 7041504162..

Issue: All requests to generateContent are blocked with:
“reason”: “API_KEY_SERVICE_BLOCKED”

Verified:

  • Generative Language API is enabled
  • Billing is active (Blaze plan)
  • API key has no application/API restrictions
  • Tested with brand new unrestricted key — same error
  • GCP dashboard shows 28 requests, 100% error rate for “Firebase AI Logic API”
  • Was working previously in this same project, stopped suddenly
  • Tested via direct curl, not just SDK — same block

Requesting help identifying why this project is blocked at the consumer level despite all settings being correct.