According to several reports, chatgpt can't be made to solve day 1. It's strongly hypothesised that Eric increased the difficulty of the problem specifically to thwart them.

Last year they fucked the global leaderboard early, then completely dropped off during week 2, so I can't say I don't welcome it. I didn't find part 2 an issue, but I completely grug-brained it and that was not sensible to the overlap issue.