Dialogue boxes for the player to respond to Niko stop appearing after starting a solstice run, even when Niko directly asks you a question. Given it was just explained that the player's capacity to interact with the world is limited to what is programmed in, it makes sense considering the entire solstice run is beyond the World Machine's programming. The fact that dialogue prompts only reappear once the World Machine learns to act beyond its programming only reinforces the notion.
During the solstice run, Niko will be able to sleep in beds whenever you check them, always saying that [they're] a little tired from walking. However, they will not have any dreams. At all. Even the ones they used to dream. How badly did the solstice run, the entire game up until the point, and by extension, you break a young child's mind that they cannot even dream anymore?