Contradiction with Matthew 14:2
Unlike in Luke 9:9, where Herod is uncertain about Jesus' identity, Matthew 14:2 implies Herod is convinced Jesus is John the Baptist resurrected.
Matthew 14:2: And said unto his servants, This is John the Baptist; he is risen from the dead; and therefore mighty works do shew forth themselves in him. [do...: or, are wrought by him]
Contradiction with Mark 6:16
While Luke 9:9 shows Herod's curiosity and his desire to see Jesus, Mark 6:16 presents Herod directly asserting that Jesus is John the Baptist risen from the dead, showing certainty rather than curiosity.
Mark 6:16: But when Herod heard [thereof], he said, It is John, whom I beheaded: he is risen from the dead.
Contradiction with John 7:12
Luke 9:9 expresses Herod's desire to see Jesus, implying curiosity and concern, while John 7:12 illustrates how people were debating Jesus' character, suggesting differing opinions on His identity rather than a singular notion of Him being John the Baptist.
John 7:12: And there was much murmuring among the people concerning him: for some said, He is a good man: others said, Nay; but he deceiveth the people.