Contradiction with Acts 9:26
Acts 9:26 mentions that when Saul arrived in Jerusalem, the disciples were afraid of him and did not believe he was a disciple, which contrasts with Acts 9:28 where he is freely moving in and out among them.
Acts 9:26: And when Saul was come to Jerusalem, he assayed to join himself to the disciples: but they were all afraid of him, and believed not that he was a disciple.
Contradiction with Acts 22:18
In Acts 22:18, Paul recalls a vision from God telling him to leave Jerusalem because the people will not accept his testimony about Jesus, contrary to Acts 9:28 where he moves freely and preaches boldly.
Acts 22:18: And saw him saying unto me, Make haste, and get thee quickly out of Jerusalem: for they will not receive thy testimony concerning me.
Contradiction with Galatians 1:17-18
Galatians 1:17-18 suggests that after his conversion, Paul did not immediately go to Jerusalem to see the apostles, which seems at odds with Acts 9:28 where he is depicted as being with the apostles.
Galatians 1:17-18: Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.