Azure: x-ace-azure-deployment is ignored or returns 400
x-ace-azure-deployment is deprecated. The deployment is the request's model (the path segment), or a per-model mapping in the stored Azure config.
Symptom
Azure OpenAI calls reach a different deployment than x-ace-azure-deployment names, or fail with HTTP 400 when the header and the model disagree.
Cause
The deployment ACE addresses is the request's model — the <deployment> path segment on /azure/openai/deployments/<deployment>/… — unless the stored Azure config maps that model to a differently-named deployment. x-ace-azure-deployment does not override model, and one that contradicts it is a 400.
Fix
Put the deployment name where the Azure SDK already does: the path segment, or model on the v1 routes. If your deployment names differ from model names, map them per model in the stored Azure config. Drop the header.