The issue is a fault in the expected behavior of the application
The issue is a suggestion of a feature being added to the official Impact build
Jun 8, 2019
Minecraft's keypress handler first runs key event listeners for any open GUI, and then after that it checks runs key binding listeners for the ingame stuff (but only if there's no GUI open).
What was happening was we would handle they key even once (and toggle off clickgui) but then no GUI was open so it would immediately handle the key event again (for ingame stuff) and toggle clickgui back on!