The armistice was signed around 5 am and due to come into effect at 11 am, partly because of the symbolism but also to make sure that all parts of the front had time to receive the message. Gunther died not because his commanders didn't get the message but because they decided to attack anyway. The Germans were shouting and waving at the Americans to go back as the war was over but they keep charging and were cut down in their hundreds. Utterly fucking pointless deaths.