Contradiction with John 4:44
This verse mentions that "a prophet hath no honour in his own country," which contrasts with the welcome reception Jesus receives in Samaria in John 4:40.
John 4:44: For Jesus himself testified, that a prophet hath no honour in his own country.
Contradiction with Matthew 10:5-6
Jesus commands the disciples to avoid visiting Gentile regions and Samaria, yet He stays in Samaria in John 4:40.
Matthew 10:5-6: These twelve Jesus sent forth, and commanded them, saying, Go not into the way of the Gentiles, and into [any] city of the Samaritans enter ye not:
Contradiction with Matthew 15:24
Jesus says He is "not sent but unto the lost sheep of the house of Israel," which contrasts with Him staying and teaching non-Israelites in Samaria in John 4:40.
Matthew 15:24: But he answered and said, I am not sent but unto the lost sheep of the house of Israel.
Contradiction with Luke 9:52-53
The Samaritans do not receive Jesus because He is headed to Jerusalem, contrasting with the reception He gets in John 4:40 where He stays and is welcomed.
Luke 9:52-53: And sent messengers before his face: and they went, and entered into a village of the Samaritans, to make ready for him.