In the video you unplug the cable from output A (working) and plug it into input B (shouldnt output anything, so also working as expected)
the arrow from input A to input B means the input is normalised from input A, it doesnt mean its the associated output for A
plugging the cable into input b breaks the normalisation, so the signal going into input a wont be passed through to input b
then you plug the first ochd signal into output A and ... yeah that makes the module work weird. its not supposed to be plugged in there.
it isnt two pairs of in/out... inputs are at the top, outputs are at the bottom (indicated by the dark ring around the socket)
That is why it isn't producing an output/behaving as you expect.
always check which are the inputs and outputs. not all modules can handle incorrect patching... it might be breaking your modules or producing weird behaviour
Merry Christmas