After updating from kOS 1.1.5.2, I ran into an awkward problem.
Spawning, or clicking on a GUI-box sets keyboard focus to that box.
The keyboard can only be used again by left clicking in-world first.
For some reason, a few keys like C, V and Arrows are exceptions.

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Test ship:

• Probe core.
• Battery.
• Scriptable control system.

Test script:

local g IS GUI(180).
set g:skin:button:width to 80.
local b1 IS g:addbutton("test").
g:show().

local keyboard_input is terminal:input:getchar().
until keyboard_input = "-"
{
	print keyboard_input.
	wait 0.0001.
	set keyboard_input to terminal:input:getchar().
}

clearguis().

Repro:

• Launch the ship, run the script.
• Use the keyboard.

Observe 1.1.5.2: All keystrokes are passed on to the world, as expected.
Observe 1.1.6.0 and later: The GUI-box has keyboard focus, all keystrokes are lost.

• Click in-world.
• Click (not drag) the GUI-box.
• Use the keyboard.

Observe: Same results.
Expected: A GUI-box only has keyboard focus when it has an active text-entry field.