Just reproduced in a clean install in a VM to rule out configuration cruft on my laptop. With plasma-workspace 5.18.5 it doesn't appear, on 5.18.8 it does, as shown in the attached video.
Just reproduced in a clean install in a VM to rule out configuration cruft on my laptop. With plasma-workspace 5.18.5 it doesn't appear, on 5.18.8 it does, as shown in the attached video.