https://v2.docusaurus.io does not load correctly on Safari for Mac or iOS

[bradumbaugh]

🐛 Bug Report

https://v2.docusaurus.io doesn't correctly load on Safari for Mac or iOS.

Have you read the Contributing Guidelines on issues?

Yes

To Reproduce

• Using Safari on a Mac
  • Safari - Version 14.0 (15610.1.28.1.9, 15610)
  • macOS Catalina - 10.15.7 (19H2)
  • Also tried this on another Mac, and on iOS 14.1. Same result.
• Visit https://v2.docusaurus.io
• Click "Get Started"
• Safari's page loading progress bar indicates the load is happening very slowly, but it never completes.
• Interrupt the reload process by hitting ⌘-R. This immediately loads https://v2.docusaurus.io/docs/.
• Attempt to twirl open the "Guides" section of the left-hand nav. Nothing happens.
• Everything seems to work fine on Chrome and Firefox.

Expected behavior

Clicking "Get Started" navigates to the docs, and the left nav works as it should.

Actual Behavior

Page doesn't load until you manually refresh. At that point, the left navigation doesn't work.

Your Environment

• Live version of https://v2.docusaurus.io - 2.0.0-alpha.67 (unreleased)
• Using Safari on a Mac
  • Safari - Version 14.0 (15610.1.28.1.9, 15610)
  • macOS Catalina - 10.15.7 (19H2)
  • Also tried this on another Mac, and on iOS 14.1. Same result.

Reproducible Demo

This issue is on the live https://v2.docusaurus.io site.