The SpongeBob Squarepants Movie (2004)

Continuity mistake: In the scene where Mindy is showing Spongebob and Patrick "Planktopolis," it shows a large fully-built statue of Plankton. A few seconds later the right side of the head is shown missing and still being worked on.

Trivia: SpongeBob has worked for the krusty krab for at least 31 years, according to his 374 consecutive employees of the month awards. He is considered a kid because sponges can live to be 500 years old.

Question: The movie was released in 2004 and Season 4 was released in 2005. In the movie, SpongeBob is the manager of The Krusty Krab 2 and Plankton got the formula but went to jail. So then how come from Season 4 onwards there's only one Krusty Krab, SpongeBob's still just a fry cook in the original Krusty Krab and Plankton's free and is still trying to get the formula?

MikeH