I do not see an issue with Firefox or Safari on my machine. Feel free to email me (jgc@cloudflare.com) with what you are seeing.

It should be working now. This was an interaction between React's streaming hydration errors (due to unexpected HTML injected by extensions) and one of the frontend dependencies.

Works for me in Firefox. Plugins maybe?

Yes, the add-on to disable Google Analytics https://tools.google.com/dlpage/gaoptout was the problem. Never had that break a web page before.