Is “Together with Ji Mao, he went into seclusion in the Southern Mountains of Wugong” true?

The official history Records of the Three Kingdoms, Book of Wei, Biographies of He, Chang, Yang, Du, Zhao, and Pei records: 'Mao, together with Fufeng Su Ze, entered the Southern Mountains of Wugong, dwelling in seclusion and thinking deeply for several years.' In Chapter 116 of Romance of the Three Kingdoms, it only writes that Deng Ai 'dispatched Yongzhou Inspector Zhuge Xu, Tianshui Administrator Wang Qi, Longxi Administrator Qian Hong, and Jincheng Administrator Yang Xin, each to transfer their own troops to come and await orders,' without mentioning Su Ze's early seclusion.