Contradiction with Acts 9:5
In Acts 22:8, the voice identifies itself explicitly as Jesus of Nazareth, whereas in Acts 9:5, there's an additional phrase, "It is hard for thee to kick against the pricks," which is not present in Acts 22:8.
Acts 9:5: And he said, Who art thou, Lord? And the Lord said, I am Jesus whom thou persecutest: [it is] hard for thee to kick against the pricks.
Contradiction with Acts 26:15
Unlike in Acts 22:8 where Jesus identifies himself, in Acts 26:15, Paul narrates the event with additional context about the Lord's command and his subsequent mission.
Acts 26:15: And I said, Who art thou, Lord? And he said, I am Jesus whom thou persecutest.