KDE Plasma 5.21.4 is here about three weeks after the KDE Plasma 5.21.3 update with another layer of improvements for the new Plasma System Monitor app to prevent the content shown in the right sidebar from getting cut off, as well as to correctly assign a color to a sensor without applying it to every one.
Also improved in this new update for the KDE Plasma 5.21 desktop environment is the Plasma Vaults app, whose subtitle for items now wraps, as well as the Klipper clipboard monitor app, which now lets you paste saved text into GTK apps in the Plasma Wayland session.