Safari 12.0 macOS Mojave version 10.14 MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports)
AS of today (2/11/2018) characters in Safari are being shown as boxed question marks.
The same websites are displayed perfectly in Firefox.
Emojis are not displayed in Messages main window but in the sidebar they are!
I have tried restore default fonts etc but no difference.