It's been like this for more than 10 days for now, I thought that maybe updating my windows would miraculously fix this but It didn't.
Beforehand, I had to press LAlt+ Shift, it switched to Japanese keyboard and then I pressed Ctrl+Caps to change to the Japanese letters input (I used Romaji input). Now, I only have PT-BR and JA-JP keyboard (Yes I'm Brazilian) and the Japanese keyboard is behaving like ENG keyboard, the Ctrl+Caps hotkey is not working as well as all the other hotkeys.
Also, my language tab is 'transparent', It used to display the language inputs but now it's literally dead, pressing it is futile. I suspect it was some build that broke it, I didn't change my keyboard, nor did I install anything to mess around with that.
NO, I didn't change my keyboard; NO, I didn't install anything (as far as I know); YES, I've tried to create another user account and seeing if it would work there but It didn't (all accounts were as administrator). YES, I've tried reinstalling the Japanese keyboard (KB3109596) [ja-JP_LP]) like 3 times already.
(WINDOWS 10)
Sorry for any misconstrual English.
