Dear ASUS: Why Did You Turn My Right Ctrl into a Puzzle?

On my ASUS ExpertBook B3404CVA running Kubuntu 24.04 (KDE Plasma 5.27.11, X11, Kernel 6.8.0-52-generic), I set the usual keyboard layout switcher via: /etc/default/keyboard: XKBLAYOUT = "us,ru" XKBOPTIONS = "grp:menu_toggle" Normally I set up layout switching through the standard graphical interface in Kubuntu — never had to think twice. But on this machine, it simply didn’t work. I had to fall back on this method. And even then, it works only intermittently : sometimes with the Fn key, sometime