library · inferred from evidence
googleapi
A library or API client referenced in the error message for the 403 authorization error.
- Cloud SQL Proxy: "Error during createEphemeral ... Error 403: The client is not authorized to make this request"
This is a known IAM propagation quirk, not a proxy bug: re-grant the role to force it to take effect. Remove the Cloud SQL Client role from the failing service account in IAM & Admin > IAM (uncheck it and Save), verify the account disappear