I followed this tutorial to install Japanese input. Unfortunately, the only place where it works for me is the search menu that is opened by pressing Super key. Everywhere else it's just regular English keyboard. I tried rebooting, uninstalling Japanese language and Mozc and then re-doing the installation process. I also tried enabling Japanese(Anthy) input source but result was the same. I also tried following the tutorial on a fresh Ubuntu 22.04 VM and it worked perfectly there. It seems that this problem is not reproducible so I'm hoping someone encountered literally the same problem and can help me.
OS: Ubuntu 22.04.02 LTS
Input method: Japanese (Mozc)
Keyboard input method system: IBus, also tried Fcitx4