Perhaps it is worth considering that this was Freestyle chess and not classical chess. Which means the traditional book moves with which chess engines are trained goes out of window. I am not saying Stockfish cant beat Magnus in Freestyle chess but it makes sense to believe that Chess engines are better at classical chess when compared to freestyle.
But then again, with 24 hour time to brute force every possible combination, I guess chess engines may be better at freestyle when compared to classical chess, due to the sheer amount of creativity and calculation involved.