KUbuntu 22.04.1, fcitx Chinese input cannot be triggered out of the box

First time using KUbuntu (22.04.1 LTS); used to use Mate & LUbuntu before, which my fcitx Chinese input had been working fine. However,

With KUbuntu 22.04.1 LTS, my fcitx Chinese input is not working out of the box -- I simply cannot get it triggered.

Here is proof that my fcitx Chinese input's installation is fine.

• On my KUbuntu 22.04.1 starts up, there are three fcitx related processes (identified by ps -eaf --width 200 | grep [f]citx):
  • /usr/bin/dbus-daemon --syslog --fork --print-pid 5 --print-address 7 --config-file /usr/share/fcitx/dbus/daemon.conf
  • /usr/bin/fcitx-dbus-watcher unix:abstract=/tmp/dbus-tW4A6FKmPk,guid=e64c862b67b86932863ee75863f14a15 5504
  • fcitx
• If I kill them all one by one, then start fcitx again manually under
  LANG=zh_CN.utf8 urxvt -ls &
  then everything is fine. Triggering hotkey is working again.

UPDATE: -- There is also an IBus Pannel icon on my KUbuntu 22.04.1 taskbar when it starts up, and I have to quit it manually each time after boot.

So it makes me suspect that the fcitx started by my KDE has the wrong setting, which what I'm trying to fix. (My normal (desktop) work environment is English, using LANG=C. The fcitx is only used for/with any applications that started under/with the LANG='zh_CN.utf8' environment, like rxvt-unicode, chrome, etc)

How to fix it? please help.

$ im-config -m
default
missing
ibus

ibus

$ LANG=C im-config -m
default
missing
ibus

ibus

$ LANG=C im-config -m | tail -3 | hexdump -C
00000000  69 62 75 73 0a 0a 69 62  75 73 0a                 |ibus..ibus.|

$ LANG='zh_CN.utf8' im-config -m
default
missing
ibus
fcitx5
ibus

Final UPDATE:

I tracked down the root reason why I have both ibus and fcitx installed. Here is why it is a bad idea first:

The reason that I have both input methods installed is because of the zoom that I need to use, and from these two pages, I can see that such requirement is really unnecessary:

1. Annoying ibus dependency in zoom .deb files
2. Zoom Debian Linux package requires ibus even on KDE and XFCE

Here are a few quotes:

• The .deb files for downloading zoom come with ibus in the “Depends:” field. That’s a problem for many Debian/Ubuntu users, and I’ll try to explain why.
• Needless to say I’m very disappointed at Zoom’s way to respond to my request so far.
• I’m working with the maintenance of a tool (im-config) used in Debian and Ubuntu to facilitate the configuration of input methods, e.g. IBus. It’s in that role I have received complaints about the ibus dependency in the Zoom .deb file, and it’s in that role I’m here.
• This is osamu@debian.org (my official Debian contact address) who is a core member of maintaining ibus package for Debian. (Gunnar is another core member too. He is heavily involved in Ubuntu side.)
• His request is not a mere “user request”. This should be considered a demand by the GNU/Linux distributions to ZOOM.
• If Zoom provide package for Debian/Ubuntu (deb-packages) with technically sound contents, ZOOM should listen to us.
• Any updates on this? Just installed zoom and got this too. This dependency is annoying and worthless
• This excuse for “remote control on a remote machine” is pathetically lacking understanding how “Depends:” field should be used for Debian package. This should be used only for packages which is required under all installation environment. Doing this for a particular environment is considered rude engineering.
• I’m a Debian Developer and hence familiar with the conventions and requirements for Debian packages, aka “.deb” files. As currently defined, the way that the Zoom Debian packages use relationship fields (such as Depends:) violate the Debian packaging policy, outlined here: 7. Declaring relationships between packages — Debian Policy Manual v4.6.1.1

However all the requests fall into deaf ears and 1 month later, "This topic was automatically closed 30 days after the last reply. New replies are no longer allowed." and that results comment from link 2:

• The Zoom Debian Linux package is requiring ibus. But ibus is part of GNOME desktop. So installing zoom_amd64.deb under KDE Plasma breaks keyboard support due to ibus and related dependencies which do not work under KDE.
• Yep, I am doing a new install of Zoom and suddenly get dependencies on ibus, libegl1-mesa, libxcb, python3-ibus, ibus-gtk and a few others. I am using a few month old Linux distro so there should be NO reason Zoom won't install. I don't need ibus, it will ruin my setup. This is just crazy. . . When a multi-billion dollar goliath like Zoom hires sub-par developers to package their software, arguably the most important job in a software firm - they deserve to fail! I read the Support forums on this same topic and the absolute failure of support staff to understand the weight of this problem was unbelievable. The Debian Maintainers of ibus made posts to try and help out, but Zoom staff ignored them. I consider this a massive failure from Zoom and a smack in the face for Linux users everywhere.