[PLASMA 5] screenlocker bug

[jduns]

After upgrading KDE Neon to plasma 5.21 (yesterday) screen locker doesn't work anymore: no more clock, no more media control, but mainly no more possibility to unlock the screen: I can see only the screensaver (correctly working as slideshow) and the cursor arrow (correctly moving if I move the mouse). But no way to unlock the screen. I have to use the magic keys to end session or reboot.
I have already filed this bug in KDE bug, but here I would ask if any other has this problem. And if there is a solution.
Thank you.

[claydoh]

No issues here on two different systems, though I do not use the slideshow option in the screen lock settings.

[jduns]

Thank you. But even after changing type of screen lock from slideshow to others, the bug remain.
If you have Plasma 5.21 and not this problem, maybe it could be a nvidia driver (that I have)? In this case should I update them?
EDIT
but I tried this

[FONT=monospace][COLOR=#000000]sudo ubuntu-drivers autoinstall [/COLOR]
Reading package lists... Done 
Building dependency tree        
Reading state information... Done 
Starting pkgProblemResolver with broken count: 0 
Starting 2 pkgProblemResolver with broken count: 0 
Done 
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.[/FONT]