AQ. format API Key returns 401 Unauthenticated Error on Gemini API

Hello Google Support Team,
I am facing a major issue with the newly generated API Key. Google AI Studio is only issuing keys starting with the AQ. prefix.

Every time I call the generativelanguage.googleapis.com endpoint (even via x-goog-api-key header), it fails with: 401 UNAUTHENTICATED — ACCESS_TOKEN_TYPE_UNSUPPORTED. The system is treating the new key format as an OAuth token instead of a standard API key.