@tges Thanks for the question. Did you try with the azure region that is near to you as Azure Cognitive Services includes 15 generally available (GA) services across 25 Azure regions.
You can avoid latency and throttling by properly configuring your environment for the amount of data you want to analyze.
As we need the logs to check, we would recommend to raise a Azure support desk ticket from Help+Support blade from Azure portal for your resource if you have a support plan for your subscription. This will help you to share the details securely and work with an engineer who can provide more insights about the issue that if it can be replicated.