Bug#973677: Confirmed even in 5.19.5-2
I (apparently) solved the problem by updating a few plasma packages to 5.19, in particular plasma-workspace plasma-desktop (and possibly one or two more). They are still at 5.17 in unstable. smime.p7s Description: S/MIME Cryptographic Signature
Bug#973677: Confirmed even in 5.19.5-2
I'm seeing the same thin even with libkscreenlocker5 5.19.5-2 from experimental. The locked screen is completely black, and wiggling the mouse shows the cursor but nothing else. My workaround to unlocking the session is to switch to a TTY shell by ctrl-shift-2, and using 'loginctl unlock-session'. smime.p7s Description: S/MIME Cryptographic Signature