Cosmos DB vCore Vector Index Error Outside US Region: InternalError & Server Shutdown (Error Code 91)

Hello,

We are encountering consistent issues when performing insert and read operations on a vector index in Azure Cosmos DB vCore outside US regions.

While performing vector operations, we get the following error:

[ActivityId=4015c5ca-fd00-cb57-18c5-3c9e06000000] An unexpected internal error has occurred
Full error: {'ok': 0.0, 'errmsg': '[ActivityId=4015c5ca-fd00-cb57-18c5-3c9e06000000] An unexpected internal error has occurred', 'code': 1, 'codeName': 'InternalError'}

Additionally, while debugging using the client library, we also observed:

Error Code: 91
Error Message: Request terminated due to shutdown on the server.

Additional Notes:

• The issue started occurring last week without any changes on our side.
• The issue does not occur when using resources in US regions.
• It only affects operations involving the vector index.
• Non-vector related queries and operations behave as expected.
• Retrying operations does not resolve the issue.

Request:

Could you please help us understand:

• Why is this internal error occurring?
• If there is a known issue with vector index support or availability in non-US regions?
• Any workarounds or timelines for resolution?

Thank you in advance for your support.