There is no contradiction between these narrations and the first narration, because the way to reconcile them is that if the garment is used exclusively by him, then whenever he finds semen on it, he must perform ghusl and repeat his prayer if he has prayed, as it is possible that he forgot the wet dream. However, if the garment is shared with others, he is not required to perform ghusl unless he is certain that he experienced a wet dream.
Commentary #3