Did this issue happen to coincide with whenever you started using a realtime kernel?
I updated to 6.14 rt a few months ago from 6.12, but I remember it was still supported (I think I looked at the Linux kernel and not for Manjaro), and after updating the kernel, fcitx, and everything else worked without a problem.
I suggest kernel 6.12 (LTS) for general stability, otherwise kernel 6.16 seems to be receiving accolades, currently.
I updated to kernel 6.16, as I had many issues with kernel 6.12. However, fcitx still doesn’t work with Wayland unless I add other environment variables.
if the issue persists, try creating a new User account (for testing purposes) to verify whether or not your issue persists in a fresh environment.
I created a new user, and on that user, fcitx worked without an issue.
One more thing I noticed is that on that user, when I do fcitx5-diagnose in Fcitx State - process, it shows two processes, fcitx and fcitx-wayland, while on my primary user, it only shows the fcitx process without the fcitx-wayland.
Do you have any ideas or suggestions on why fcitx-wayland doesn’t start, even after I set the virtual keyboard to fcitx 5 wayland launcher, as it is the same settings as on the test user?