[Problem] Ubuntu input sluggish or ignoring keys - wxMaxima-developers/wxmaxima GitHub Wiki
Symptom
Input sometimes is sluggish or ignoring keys on Ubuntu.
Suspected diagnosis
The package ibus-gtk is missing.
Possible cure
Installing the package ibus-gtk should resolve this issue. See (https://bugs.launchpad.net/ubuntu/+source/wxwidgets3.0/+bug/1421558) for details.