Replace
{down = iCommandHelicopter_CollectiveStopper_Up, up = iCommandPlaneCollectiveStop, name = _('STO STOP UP'), category = _('Flight Control')},
{down = iCommandHelicopter_CollectiveStopper_Down, up = iCommandPlaneCollectiveStop, name = _('STO STOP DOWN'), category = _('Flight Control')},
With
{pressed = iCommandHelicopter_CollectiveStopper_Up, up = iCommandPlaneCollectiveStop, name = _('STO STOP UP'), category = _('Flight Control')},
{pressed = iCommandHelicopter_CollectiveStopper_Down, up = iCommandPlaneCollectiveStop, name = _('STO STOP DOWN'), category = _('Flight Control')},
in the joystick\default.lua that you downloaded