Although Jun Wu Xie wanted to go back sooner to check if there would be any rune totems among the Twelve Palaces, it was still at least a month or two till the time that the bodies of Qiao Chu and the others would fully recover. And if Jun Wu Yao and Jun Wu Xie were to leave, then it would be very tough for Qiao Chu and the companions to leave the Spirit World.
It was Jun Wu Yao who came up with a solution to that. He left the Spirit World first temporarily, and handed the task of searching for the rune totems over to Ye Mei and the others.
And over that period, Jun Wu Xie and her companions used the time to continue with their cultivation, to increase their power of the spirit as much as possible, as only by strengthening their spirits would they be able to make themselves much more invincible.