In Kung Fu Panda: Legends Of Awesomeness, the Sacred Peach Tree Of Heavenly Wisdom disintegrated. But in this movie, it was still alive.
In one scene Po removes cover and put aside to enter a tunnel, but later when he is entering, the cover was not seen where he put it.
At the beginning of the movie, The Chameleon's voice sounded like Tai Lung's voice when she shape-shifted into him. But when she was fighting with Po, she sounded like Tai Lung and herself at the same time when she shape-shifted into him again.
The chameleon says her reason for seeking to steal the Kung Fu powers of the previous films' villains is that she always wanted to learn Kung fu, but was rejected from schools for being too small. This doesn't make sense, as mantis is obviously much smaller than her and he himself became a Kung Fu Master.
Despite the fact that he was erased from existence in the 3rd movie, Kai was summoned by The Chameleon.
In Kung Fu Panda 2, Po found inner peace. But in this movie, he was trying to find inner peace again.
When Zhen tried to break the Urn Of Whispering Warriors, Po told her that he broke it twice. But in the 1st movie, he broke it once. And then, his biological father, Li Shan, broke it in Kung Fu Panda 3. Also, Po broke it in Kung Fu Panda: Legends Of Awesomeness, and it happened 2 times.
In the Kung Fu Panda TV shows, Kung Fu Panda: The Paws Of Destiny and Kung Fu Panda: The Dragon Knight, people acknowledged Po's title as the Dragon Master. But in this movie, which takes place after the events of the aforementioned TV shows, they acknowledged Po's title as the Dragon Warrior, just like in the previous movies.
In the 1st Kung Fu Panda movie, Po and Tai Lung were the same height. But in this movie, Tai Lung was taller than Po.
When The Chameleon shape-shifted into Tai Lung for the 1st time, her eyes were gold. But when she shape-shifted into him for the 2nd time, her eyes were blue.