Web Search fails with a response decoding error when using gpt-5.6-sol

What version of Codex CLI is running?

0.144.1

What subscription do you have?

plus

Which model were you using?

gpt-5.6-sol

What platform is your computer?

windows

What terminal emulator and version are you using (if applicable)?

powershell 7.5.8

Codex doctor report

What issue are you seeing?

Model

Affected model: gpt-5.6-sol

Description

Web Search repeatedly fails when the selected model is gpt-5.6-sol.

In the same conversation and environment, the query succeeded before switching
models. After switching to gpt-5.6-sol, the identical query failed repeatedly
with a response decoding error.

Model selection was the only observed variable. This suggests a model-specific
Web Search integration, routing, or response-handling issue, although I cannot
determine the exact root cause from the client side.

What steps can reproduce the bug?

Steps to reproduce

1. Open a Codex conversation with [working model name].
2. Ask Codex to perform a Web Search for OpenAI official website.
3. Confirm that search results are returned.
4. Switch the conversation to gpt-5.6-sol.
5. Repeat the same Web Search.
6. Retry the search or use another query such as site:openai.com OpenAI.

What is the expected behavior?

Every Web Search attempt with gpt-5.6-sol fails with:

Fatal error: stream error: failed to decode search response:
expected value at line 1 column 1



### Additional information

1.The identical query had succeeded before the model switch.
2.The failure was reproduced multiple times after switching to gpt-5.6-sol.
3.No environment, network, or permission settings were changed.
4.I can provide additional diagnostics or a conversation/task identifier if
5.maintainers indicate a safe way to share it.