Contradiction with Matthew 10:5-6
This verse instructs to not go into the way of the Gentiles, whereas Acts 14:7 describes the preaching of the gospel to all, including Gentiles.
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 states He was sent only to the lost sheep of Israel, contrasting with Acts 14:7 where Paul and Barnabas preach the gospel broadly.
Matthew 15:24: But he answered and said, I am not sent but unto the lost sheep of the house of Israel.
Contradiction with Matthew 28:19-20
Contradicts by commanding to baptize all nations, while Acts 14:7 shows preaching without mention of baptism.
Matthew 28:19-20: Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: [teach...: or, make disciples, or, Christians of all nations]
Contradiction with Romans 15:20
Paul aims not to preach Christ where He was already named, contrasting Acts 14:7 where they preach to regions that might have heard before.
Romans 15:20: Yea, so have I strived to preach the gospel, not where Christ was named, lest I should build upon another man's foundation: