It's been a long while but I think back to the future manage to squeeze in two sequel without retcon the character.
Also Cloudy With a Chance of Meatball 2 is so guilty of this, they have to change so much to fit in the villain of the movie. Also Sam and Manny is somehow a resident of Swallow Falls that is now displaced, despite being based in New York and travel to Swallow Falls for the news coverage. The whole plot is mediocre too.