I was about to post the EXACT same about Chat.
I have found the culprit, after disabling everything and going on-by-one.
@Aslain
If "Improved Chat v3" IS enabled, it acts like the "Disable Battle Chat" option, aka. there is no ingame chat, no matter how hard you mash the Enter key.
Uninstalling "Improved Chat" fixed this issue.
(not adding logs because I lost enough Battle time figuring this out, do not want to install it again just so I can provide logs)