When Naomi Scott's character Skye, is modeling in a photo shoot. The photographer has a camera with only a lens attached. In the next shot, the same photographer is shown, but their camera now has a remote flash trigger attached to it. Then in the next shot, the trigger is gone again.
Barbara Gallagher's dress color changes from black, when she approaches Skye, to blue, when Skye knocks her off the stage, in the immediate following shot.
In the beginning of the film, Joel tries to get rid of the curse by killing a person and having a witness, passing the curse forward to said witness without him dying. It is unknown how he knew about this method of getting rid of the curse, as Rose Cotter did not tell him about it in the first film, although it might be possible he discovered in the same way Robert Talley did, by researching it online.
In one scene Skye places a Voss water bottle down on a stone/marble kitchen counter and a noise matching the sound of something plastic being placed down is heard. Voss water bottles are glass, something that is actually specifically highlighted in the film, and so the audio doesn't match the action seen.
While the film takes place in New York City, when Skye and Gemma are driving out of the city to Staten Island, the very last part of the shot is with mountains in the background...clearly upstate NY where the movie was shot.
While getting make up on the main character has a mole on one side, next scene is on the other.