SUMMARY:
Accent and dead key input (e.g. `^`, `¨`, `ê`, `ë`) is no longer working in certain applications since a recent update of KDE Neon under Wayland. The issue appears app-specific (e.g. affects Vesktop and LM Studio for me), and was not present before the update.



STEPS TO REPRODUCE:
1. Use KDE Neon (Plasma 6.4.2) under a Wayland session.
2. Launch an application such as Vesktop (Flatpak) or LM Studio (AppImage).
3. Try typing characters using dead keys (e.g. `^` then `e` → `ê`, or `¨` then `e` → `ë`).



OBSERVED RESULT:
Dead keys like `^` or `¨` produce no character and do not combine with the following letter. The accent input is completely ignored in some apps.
Other apps (like Discord Flatpak) behave correctly and allow proper input of accented characters.



EXPECTED RESULT:
Dead key input should function consistently across all applications in the Wayland session, as it did before the recent KDE Neon update.



SOFTWARE/OS VERSIONS:
- Operating System: KDE neon User Edition
- KDE Plasma Version: 6.4.2
- KDE Frameworks Version: 6.15.0
- Qt Version: 6.9.0
- Kernel Version: 6.11.0-29-generic (64-bit)
- Graphics Platform: Wayland
- Processors: 20 × 13th Gen Intel® Core™ i7-13700H
- Memory: 32 GiB
- Graphics: Intel® Graphics + NVIDIA GeForce RTX 4060 Laptop GPU (hybrid)



ADDITIONAL INFORMATION:
This issue did not exist before (under Wayland). It appeared recently, presumably after the latest KDE Neon update I did.

The problem can be worked around by manually setting environment variables before launching affected applications:

GTK_IM_MODULE=ibus
QT_IM_MODULE=ibus


Creating a persistent fix (e.g. in `~/.config/environment.d/immodules.conf`) resolves the problem system-wide.

This may suggests that the KDE Neon Wayland session does not export proper input method environment variables by default, which may break accent/dead key input in some apps that depend on them.

It would be helpful if KDE Neon set these variables by default for Wayland sessions to ensure full compatibility.