PSG have a great mentality and toughness in dominating the domestic league so far, but this mentality and toughness they do not have when playing in Europe, especially the UCL so far, even when they have many star players in the squad, their best achievement in the UCL is only until the final without being able to win the championship trophy, They actually have a strong squad with great players but the easy competition in the league has actually shaped their poor mentality in the UCL, in my opinion, before PSG is able to improve their mentality to be better and stronger, then we will never see PSG win the UCL and this season is likely to be their worst journey in the UCL.
One major issue I seem to have observed around PSG that has caused them the inconsistencies in the champions League is their tactical approach and their mentality towards the game, they have a good team such that it cannot and never be blamed on the players, neither the coach but I will throw slight blame at him in that he's the person in charge a d picks the strategies they use at any time but then he's got a technical crew he works with so that makes it such that it's to be evenly blamed amongst them all, hopefully with time they will be able to find a sound tactics around the UCL just like they have done