Hi - on the Discord Mike said that global chat is sharded by language[1].
While playing, Judd’s messages indicated he was talking to people whose messages we could not see. Another player confirmed that his group could all see different messages.
JPEG in zip (536.6 KB)
If this is the case, then there is a bug in the chat system 
Player.log (2.0 MB)
[1] Source: Discord