The biggest change in Nitrux 1.3.8 is the upgrade to the latest and greatest KDE Plasma 5.21 desktop environment, which brings numerous new features and improvements. In fact, the first point release, KDE Plasma 5.21.1, is used in this new Nitrux version. The KDE Plasma 5.21 desktop environment in Nitrux 1.3.8 is accompanied by the latest KDE Frameworks 5.79 and KDE Applications 20.12.2 open-source software suites, and features a new default window decoration forked from SierraBreezeEnchanced. In addition, the Nitrux devs fixed the missing Night Color Control icon, reduced the height of the title bar and addresses some minor glitches on the sides of the title bar, and fixed unusable window buttons when using other button sizes than the default ones.