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

Using version 3.6.3 with docs module, navbar is rendered as hamburger menu on landing page with empty contents, however it's not seen on desktop version.

You can test it live on the webpage I'm setting up: privacylearn.com

Reproducible demo

No response

Steps to reproduce

1. Open website in mobile
2. On top right, hamburger menu is visible, clicking on it results in empty list

Expected behavior

No menu on mobile, just like on desktop for consistency

Actual behavior

Hamburger menu is visible, clicking on it results in empty list

Your environment

No response

Self-service

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