The Duo Chat `/clean` command times out in VSCode

Summary

/clean works in the web UI, but in VSCode it times out.

Steps to reproduce

1. Open the Duo Chat panel in VSCode.
2. Enter something to start a conversation (e.g., help)
3. Enter /clean

What is the current bug behavior?

It says GitLab Duo Chat is finding an answer for a while and then Reached timeout while fetching response.

What is the expected correct behavior?

The history is cleared, like it is when you use the command in the web UI.

Environment info

Environment: GDK (self-managed)
GitLab version: GitLab Enterprise Edition 16.8.0-pre 213aa680.
GitLab Workflow version: v3.99.0
VSCode version info:

Version: 1.85.1 (Universal)
Commit: 0ee08df0cf4527e40edc9aa28f4b5bd38bbff2b2
Date: 2023-12-13T09:48:06.308Z
Electron: 25.9.7
ElectronBuildId: 25551756
Chromium: 114.0.5735.289
Node.js: 18.15.0
V8: 11.4.183.29-electron.0
OS: Darwin arm64 23.2.0