Hi Marc,
Thank you for reaching support. The error received could be a transient error. Could you please retry the request? If you're still facing an issue, could you please share the request and response logs where you're receiving this error to investigate further? Also, could you confirm if you are observing this consistently with all the API service calls? Please share the details privately via Reply privately to author option.
Regards,
Nikisha Patel, Google Ads API Team