Their defeat against Chelsea must have spurred them on. I think they'll make fewer mistakes in the Champions League. Their performance against Real Madrid was superb, and they dominated the game and won. This match demonstrated just how dangerous Paris Saint-Germain is. They're clearly in a position to be one of the best teams in Europe right now. Their loss to Chelsea led to numerous moments where they analyzed and recognized their mistakes. Next year's Champions League is even more important for manager Luis Enrique.
The loss they suffered against Chelsea was not about mistakes, PSG did not make too many or even enough mistakes to say there was any in that game, for me it was more about the mentality, the mentality of the team was one of the factors that gave them such loss and the coaches tactical approach to that game. The mentality and reluctance they played that game was too much, one they never displayed against Madrid so it was not at all about any mistakes but they will have definitely learn and will be poised towards making up for such and hopefully in the champions league they do not repeat such with any team.