Keys stuck when trying to press multiple ones and release them at the same time. Xev output shows that only one KeyRelease event is fired (doesn't matter how many keys were pressed - 2,3, so on). This produces "sticky keys" bug in some cases, however not when typing. Ubuntu 18.04, with installed xubuntu-desktop. In gnome desktop everything works fine though. How can I fix it, or at least find out the reason of that behavior?