Because they don't care about fooling you ('the West'). It was done for internal consumption, as usual. I expect them to put the blame on Ukrainian diplomats in the evening news.
I believe it could be also an excuse to justify ( internally ) why the war is going so slow. "It is not that Ukrainians don't want to be saved and are fighting hard, it is because we want to give them opportunities for diplomacy and we stopped the hostility for a day"