Plot hole: When Chucky is decapitated, no blood comes out. He still has the scars from Bride/Seed of Chucky so that means he's still in the same doll's body. The longer he remains inside the doll the more human he becomes, so he should definitely bleed by this point in time.
Curse of Chucky (2013)
1 plot hole - chronological order
Directed by: Don Mancini
Starring: Brad Dourif, Alex Vincent, A Martinez, Danielle Bisutti
Continuity mistake: Barb's eyes are green throughout the movie, but when Chucky stabs her in the eye, the eyeball that rolls down the steps is blue.
Trivia: The appearance of Charles Lee Ray on-screen during the flashback sequences marks the first time that Brad Dourif had appeared in human form in one of the "Chucky" films since the original. (Although photos of him from the original did subsequently appear in the other sequels, he had not shot any new live-action material in 25 years).
More questions & answers from Curse of Chucky
Suggested correction: There's no telling exactly how his Voodoo works.
The writer/director even admitted this scene was a mistake. Prior films showed that once Chucky inhabited the doll for long enough, blood and organs would appear. The director simply chose to ignore this for this one scene, and has admitted it's a mistake.
TedStixon