we had a backport of fcitx to have it rebuilt against our Qt. otherwise people have a hard time with CJK input. it seems to not have made its way into bionic. a quick look at packaging.neon makes me think it was one of the incorrect forks/ but missed in the move to backports. So, there should be a fcitx backport-bionic made.
https://forum.kde.org/viewtopic.php?f=309&t=154174&p=405649#p404520