I think you're reading too much into things, or simply not reading the story.With the new update I hope there is some reaction from Felix. On Sophie's side, it is expected that her sexual history with Zack and the humiliation towards Felix will continue to grow. But the story from Felix's vision needs some action, I understand that the story needs a submissive and humiliable husband but it is half reaching a very illogical level beyond the trust that he continues to have for Sophie, basically they no longer live as a couple and that He accepts it so placidly that it becomes very annoying to follow his route. She has practically spent the entire month living with Zack with an excuse that is no longer sustainable, in addition they do not have sex or closeness of any kind, they do not even have lunch together anymore since she goes for sex with her lover and he as if nothing had happened. At first it was understandable that Sophie's escapades were much more sporadic. It's good that the reason for Felix's route is to have the vision from the cuckold but it is losing its appeal I think.
No, Sophie did not live with Zack for a month or anything of the sort.
The story does skip a lot of the mundane boring day-to-day stuff, because who would want to read that, but that doesn't mean that 90% of the time things aren't normal between Sophie and Felix.