STEPS TO REPRODUCE
1. open Accessibility KCM
2. close System Settings without changing anything
the save/discard prompt shows up
System Settings closes
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.27.80
KDE Frameworks Version: 5.240.0
Qt Version: 6.5.1
Graphics Platform: Wayland
Cannot reproduce this one.
I can confirm this one when opening Accessibility from Kickoff. If I open it via kcmshell6 access it works fine.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/1692
Fixed by Jürgen Dev with https://invent.kde.org/plasma/plasma-desktop/-/commit/3d9d4e9016015a07f7652456c0873f9f5582ad01 for Plasma 5.27.8 too.