Worshipper – “The Pledge” [Campaign 2, Mission 2]

Campaign 2, mission 2. I can't complete this mission. It doesn't seem to have a time limit; the main objective is to arrive before the opponent. I reach the Mausoleum of Kings, defeat the blue player guarding the Mausoleum, and immediately engage in a battle with the orange player, after which nothing happens. I don't receive the Griffin Heart. I can return to the path I came from, traverse it, and approach the mausoleum again, but if I leave the sand and step onto the orange hero's path, I can no longer return to the Mausoleum. What should I do?