Compose key and IBus IME doesn't work

It used to work before on the same system.
Ubuntu 22.04
Gnome (Xorg)
XIVLauncher from ppa

Hmm, I had XMODIFIERS hack on. So maybe it's my fault after all.
Compose key started working.
Japanese IME doesn't though.

[Rafagd]

I'm having the same issue with portuguese accents (eg. ´ + e = é or ~ + a = ã).
Debian Trixie
KDE Plasma 6.2.4 (wayland)
XIVLauncher from make-deb

@Nekotekina Can you explain me the hack just in case I've done it in the past and need to undo it?

Edit: For the sake of documentation, the problem was on the im-config package.
Running im-config → OK → Yes → do not activate any IM from im-config and use desktop default → OK solved the problem.
Source: https://discuss.kde.org/t/ibus-issue-with-wayland/3680/12