The main homework of several teams such as Bayern Munich and Paris Saint Grmain is the Champions League, they don't need to be doubted in the domestic league because they have enough strength to defend their current title. But when moving to the Champions League it will be something different, this is inseparable from the competition in the Champions League is very tight. Once they make a mistake they will receive a penalty by being eliminated by the other team.
The two teams always give their best contribution to play well so as not to make even the slightest mistake because indeed when a small mistake occurs it will be taken advantage of by the opposing team who is ready to attack, Bayern Munich managed to maintain its best position to stay on top while for Paris Saint Germain still can't get successive wins like Bayern Munich did.