The stage play Harry Potter and the Cursed Child changed the way Time-Turners work in the wizarding world and retconned the plot of Harry Potter and the Prisoner of Azkaban. The sequel to the Harry Potter series sees the return of the small time-traveling devices, which were already thought to cause plot holes since they could be used to zip back and time and solve all of Harry's problems. The Prisoner of Azkaban book proved that this wasn't the case, but Cursed Child's plot ruined this explanation—ultimately creating even more plot holes.
from Screen Rant https://ift.tt/hy7clVv