Bug 443957

SUMMARY
Since updating to plasma 5.23.0/frameworks 5.87.0 most keyboard modifiers are completely non functional in wayland apps, although they seem to work as expected in xwayland apps.

Most keyboard modifiers such as Ctrl+C, Ctrl+V, Capslock/shift for capital letters, Meta or Alt+F1 to open klauncher/kickoff. Caplock light, etc, do not work.

Some modifiers do work, such as Shift and +/_ or Alt + G.

Keyboard shortcuts/modifiers work as expected in X11 session. They also worked as expected in the wayland session in 5.22.5/5.85.0.

Keyboard layout is US intl with dead keys. Although I've also tried bog standard US layout to no avail.

When attempting to change a keyboard shortcut the shortcut editor only seems to capture one key, if that helps. If I press Alt+F1 it captures Alt but overrides it F1 when the second key is pressed for example.

STEPS TO REPRODUCE
1. Login to wayland session
2. Try to use a keyboard shortcut/modifier such as Meta or Alt+F1 to open kickoff. 
3. Try to use caplock, Ctrl+C/V/A in konsole.

OBSERVED RESULT
Keyboard shortcuts/modifiers do not work.


EXPECTED RESULT
Keyboard shortcuts/modifiers should work as expected.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Solus
(available in About System)
KDE Plasma Version: 5.23.0
KDE Frameworks Version: 5.87.0
Qt Version: kde/5.15 branch (sept 20th/21)

ADDITIONAL INFORMATION
My distribution last synced with the qt kde branch on Sept. 20th, let me know of any commits i should try and backport. Happy to try and backport commits in general.