Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

In https://docusaurus.io/docs, I can see collapse side bar button at the bottom left.
And when I collapse it, it turns weird.
The way to solve this problem is clicking menu that can expand.

I think bug happens because there is a problem between expand menu button and collapse side bar button.

Reproducible demo

No response

Steps to reproduce

Visit https://docusaurus.io/docs and act like the video above.

Expected behavior

It need to collapse and expand properly.

Actual behavior

It works something weird.

Your environment

• Public site URL: https://docusaurus.io/docs
• Docusaurus version used: Maybe latest version (2.4.0)
• Environment name and version (e.g. Chrome 89, Node.js 16.4): Chrome
• Operating system and version (e.g. Ubuntu 20.04.2 LTS): MacOS

Self-service

• I'd be willing to fix this bug myself.