SUMMARY
in 100% of instances after wakeup from sleep as well as in half of normal locks (e.g. with meta+L) the screen locker dies with the following error:
> The screen locker is broken and unlocking is not possible anymore. In order to unlock it, switch to a virtual terminal (e.g. Ctri+Alt+F2), log in to your account and execute the command: 
> loginctl unlock-session 10 
> Then log out of the virtual session by pressing Ctrl+D, and switch back to the running session (Ctrl+Alt+F4). Should you have forgotten the instructions, you can get back to this screen by pressing Ctrl+Alt+F4

pressing the power button again at this stage (which normally goes to sleep) kills the user session and goes to First Unlock, after which the user session starts as if after boot.

STEPS TO REPRODUCE
1. have the laptop go to sleep (due to inactivity, due to action configured as sleep etc.)
2. wake up from sleep

OBSERVED RESULT
screen locker gets broken

EXPECTED RESULT
screen locker appears normally.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux Asahi Remix 42
KDE Plasma Version: 6.4.1
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.14.8-400.asahi.fc42.aarch64+16k (64-bit)
Graphics Platform: Wayland
Product Name: Apple MacBook Pro (14-inch, M1 Pro, 2021)

ADDITIONAL INFORMATION
this seems to be new behaviour from today, following some updates likely installed yesterday.