Regarding fcitx5 issues, probably the best advice is “If you don’t use or need it, uninstall it”. These 2 comments from 357194 – Chosen keyboard layout doesn’t work when plasma-desktop reboots with fcitx5 sum it up fairly well:
cwo 2025-02-11 22:15:26 UTC
How do I make sure that I have English and Russian so that I can switch
between them as before and the keyboard shortcuts always work?Easiest way is to uninstall fcitx5. You don’t need an input method to type English and Russian, regular keyboard layouts are absolutely enough. Input methods are relevant for languages that have way more characters than keys (think Chinese or Japanese where you have thousands of different characters that you need to be able to type). Without fcitx5, you can just use Plasma’s keyboard layout configuration and it will remember the layouts.
If you do want to have fcitx5 installed, you need to configure everything in fcitx5 which is rather more complicated than the plasma default because it does so much more. fcitx5 needs to take over the keyboard configuration from Plasma so that switching between languages works with input methods. There is a separate System settings module for fcitx5 (kcm-fcitx5), and you will probably also want kimpanel through which you can setup fcitx5 as well. If you do, you can just ignore the keyboard configuration in Plasma itself; it will not apply.
cwo 2025-02-15 12:27:58 UTC
Then your options are as outlined in comment #12. Either uninstall fcitx5 if you do not actually need it, or use fcitx5 to configure your layouts and switching, not Plasma’s keyboard settings in System Settings > Keyboard. fcitx5 takes over keyboard layouts when it’s started, and replaces it with the ones configured in fcitx5 so that it can function properly. We know this is not optimal, but at the moment you cannot use Plasma’s Keyboard layout configuration if you’re also using fcitx5, it will be regularly overwritten. (You can install kcm-fcitx5 if you want to configure fcitx5 in System Settings, but it will not appear in the Keyboard settings; it’s under Language & Time as “Input Method”).
And if you do use fcitx5, make sure you have fcitx5-configtool installed so you can set up your keyboard layouts. The fcitx5 wiki may also be useful - something I posted in the Stable Updates thread:
It is getting a little confusing having 2 open Testing Update threads, especially as the 2025-02-19 Testing Update included a Plasma bugfix update from 6.3.0 to 6.3.1, which means some issues here may already be fixed. So, I think I will close off this thread.