Bug 460353

SUMMARY

I use my laptop usually with an external screen connected as the only screen (with the laptop lid closed and an external keyboard and mouse), mention this just in case it's relevant.

STEPS TO REPRODUCE
1. Leave my computer unattended for several minutes
2. The screen automatically locks and later turns off
3. shake the mouse > the screens turns on and the password prompt show up
4. Type in the password to unlock and resume working

OBSERVED RESULT

Most of the times this all works as expected, but from time to time, the password prompt goes completely berserk, becomes unresponsive, the screen flickers, and it's impossible to enter the password and unlock.

Sometimes the password prompt doesn't even show up, only the background screen (then some random sequence of clicking, shaking the mouse, hammering the keyboard, sometimes makes it show up, but still unresponsive and not working).

Sometimes, not always, by just switching to a virtual tty and back (e.g. Ctrl+Alt+F2, Ctrl+Alt+F1) just magically makes it work.
When it does not, it still usually causes all the characters that you had been hitting on the keyboard that hadn't shown up, to show up in the input box (obviously as bullets, not the actual characters).

When switching to the tty, I tried logging in and running some commands. Top doesn't show any unusually high CPU or memory consumption by any process.

The only thing that I was able to do to be able to resume working was to kill xorg, but obviously I lose the session and any unsaved work, it's just the same as rebooting, it's not a workaround.

Before that, I  tried killing the "plashashell" process and that didn't help. 

I had this EXACT SAME PROBLEM on OpenSUSE Tumbleweed and now I have it on a freshly installed Manjaro Linux.


EXPECTED RESULT

Obviously should always work


SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Kernel Version: 5.15.71-1-MANJARO (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-1065G7 CPU @ 1.30GHz
Memory: 7.3 GiB of RAM
Graphics Processor: Mesa Intel® Iris® Plus Graphics
Manufacturer: LENOVO
Product Name: 81WE
System Version: IdeaPad 3 15IIL05

ADDITIONAL INFORMATION