Ok, i played 60 hours with keyboard. And now i watched the mouse mode. Omg… auto-attack, easy searching for hidden bosses and quests? What is this? Why i must search every corner of the map with keyboard, when with mouse i do it within few seconds?
Always check the setting when you first played the game. Hope that gave you an lesson.
Although so, mouse mode is super buggy in this game, its better to just play keyboard mode as a melee character.