Is “Cut the mat and sat apart from Hua Xin” true?

The official history 'Records of the Three Kingdoms', Book of Wei, Biographies of Huan, Two Chens, Xu, Wei, and Lu, only records: 'When the office of Situ was vacant, Yu recommended the hermit Guan Ning, but the emperor did not employ him.' In 'Romance of the Three Kingdoms', Chapter 66, it is described in detail: 'Ning sat upright without moving, while Xin abandoned his book to go watch. From then on, Ning despised Xin's character, so he cut the mat and sat apart, no longer treating him as a friend.'