Revealing mistake: After young Donna and Bill are swimming back to the boat after what is meant to be a beautiful ocean swim, Donna climbs up into the boat. In the high shot we can see a line or seam in the floor under the water that gives away it's being shot in a pool.
Mamma Mia! Here We Go Again (2018)
1 revealing mistake
Directed by: Ol Parker
Starring: Meryl Streep, Amanda Seyfried, Christine Baranski, Lily James
Factual error: The opening scene shows Donna graduating from New College in 1979. That is not possible, women were only first admitted in 1979.
Trivia: Meryl Streep filmed all of her scenes in less than a week.