### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

A bug happened! Why, when using litellm and the `response` return interface, does the `azure gpt-5.1-data` stream return all data at once, while `azure gpt-5.4-data` returns data in a streaming format? Is there a specific configuration setting for this, and why doesn’t `5.1-data` return data in a streaming format?

### Steps to Reproduce

1. 2. 3.

### Relevant log output

```shell

```

### What part of LiteLLM is this about?

_No response_

### What LiteLLM version are you on ?

v1.88.0

### Twitter / LinkedIn details

_No response_