I’m running Fedora 38 KDE spin. The problem is with ibus candidate selection window. For some apps the candidate selection window does follow the insertion pointer of what I’m typing. But for some other apps that window shows up either on the top-left corner of the screen or at the latest position for the previous issueless app.
The apps that work perfectly with ibus for me: Discord, OnlyOffice, Google Chrome
And the apps that show this issue: Firefox, LibreOffice, Telegram
These are the ones I’ve tested so far.
I’m running this on wayland. Everything works fine on X11.
Unfortunately ibus is known to have issues in KDE on Fedora: Issue #166: ibus bugs on Kinoite also KDE-Spin - SIG - Pagure.io
The problem only occurs on wayland. and I do not face any other issue than this one on wayland with ibus. I do not face the issues you mentioned in the link. I have my keyboard shortcuts working and everything else is working fine too.
On x11 though everything works fine with ibus. But I have to use wayland.