Contradiction with John 18:2
In John 18:2, Judas is said to know the place where Jesus went often with his disciples, but it does not specifically mention a betrayal with a kiss.
John 18:2: And Judas also, which betrayed him, knew the place: for Jesus ofttimes resorted thither with his disciples.
Contradiction with Matthew 26:49-50
In Matthew 26:49-50, Judas immediately approaches Jesus to kiss Him, but Jesus calls him "friend" and asks him why he is there, without highlighting the act as a signal of betrayal.
Matthew 26:49-50: And Jesus said unto him, Friend, wherefore art thou come? Then came they, and laid hands on Jesus, and took him.
Contradiction with Mark 14:44
Mark 14:44 describes Judas giving a prearranged signal to identify Jesus, but it emphasizes the act rather than a parallel dialogue occurring with a crowd as in Luke 22:47.
Mark 14:44: And he that betrayed him had given them a token, saying, Whomsoever I shall kiss, that same is he; take him, and lead [him] away safely.
Contradiction with John 18:5-6
In John 18:5-6, Jesus identifies Himself to the arresters, which results in them falling backward, contrasting with the immediate progression of events after Judas' kiss in Luke 22:47.
John 18:5-6: They answered him, Jesus of Nazareth. Jesus saith unto them, I am [he]. And Judas also, which betrayed him, stood with them.