Yes, he didn't play the ATP Finals definition well and the Serbian wolf ate his entire prey mercilessly.
But, he quickly vindicated himself in the Davis Cup Finals, giving him a taste of his own medicine, saving three match points against him and in the Australian Open he finished with the longest winning streak of his rival, ending his invincibility in the semifinals, comfortably winning the match, except for a distraction in the third set.
Of course, he should never lose again against his opponent who is 14 years older, since unlike Alcaraz, the good sinner is already in his prime and has no excuses for having a negative result against him from now on.