It's a feature of canon! Shen Yuan died and ended up in the webnovel Proud Immortal Demon Way as Shen Qingqiu, Luo Binghe's teacher and the villain of the story! Shen Qingqiu thinks he knows how the story goes, which causes tragic misunderstandings later when he thinks he knows what Luo Binghe is thinking. So here the plot of SVSSS is derailed bc Shen Qingqiu isn't going to be as focused on what happened in PIDW!