Twenty Twenty seems to be broken on mobile views, the styles for the button are not being applied:

This seems to only be broken on WordPress.com sites, not on Jetpack or local installs.
Oddly things work just fine in the iOS simulator, but not on an actual device.

@apeatling Is this due to it still being a beta block. Accessing the site via the iOS simulator would still be using your proxied connection?
I added the jetpack-beta-blocks sticker to a test blog of mine and refreshing the page on my iPhone now gets the CSS.

@aaronrobertshaw Yes! That's exactly what it is. Good sleuthing!
Closing this because it will be fixed once this launches fully.