@Bim A bit of a triple post from me, sorry.
There are also issues using Chatbox 3.0.1 from browsers on iOS and IE11 on Windows.
I checked console on IE11 and it's complaining of a JS issue:
Also, skin tone changes appear oddly:
I upgraded to IPS 4.3 today and have updated Chatbox to 3.0.1. Emoji don't seem to be working (I'm using Twitter style emoji only).
I've resaved all front templates, have cleared cache, etc., but still no luck.