Did Jesus Perform Any Signs? If He Did Then How Many?

There is a contradiction in the Bible. In one verse we read that Jesus said that no sign will be given to his generation:

Mark 8:11-13
The Pharisees came and began to question Jesus. To test him, they asked him for a sign (semeion) from heaven. He sighed deeply and said, "Why does this generation ask for a miraculous sign (semeion)? I tell you the truth, no sign (semeion) will be given to it."Then he left them, got back into the boat and crossed to the other side.

However, in another place it says that his generation would be given the sign of Jonah...

Matthew 12:38-39
Then some of the Pharisees and teachers of the law said to him, "Teacher, we want to see a miraculous sign (semeion) from you." He answered, "A wicked and adulterous generation asks for a miraculous sign (semeion)! But none will be given it except the sign (semeion) of the prophet Jonah.

Some Christians might try to say that Jesus meant that they would not receive a sign from heaven in Mark 8; however Jesus made it clear that they would not receive any semeion and did not specify which kind. Jesus said no semeion would be given to his generation. However, we don't see this in Matthew.

Now obviously when Jesus was talking about giving the people the 'Sign of Jonah', he was referring to his alleged resurrection. (What would be miraculous about him dying and being buried?)
Another question that arises is the issue regarding all of Jesus' other miracles such as healing the blind, the leper, resurrecting the dead and feeding thousands with a little amount of food. Aren't all of these miracles considered signs?
Either there is a discrepancy between Jesus saying that he will give NO SIGN to the Jews except the sign of Jonah and him doing other miracles such as healing the blind and raising the dead.
Or the other option is Christians stating that Jesus' healing of the blind and his raising of the dead were not miracles or signs of his Prophethood. But that makes no sense. If they were not signs, then why would Jesus perform these miracles?
Someone might argue that Jesus meant to say that he would give no sign afterwards from that particular point in time. However, this could easily be refuted by simply reading on after that passage and seeing passages such as Mark 8:22-26, which show that Jesus healed a blind man or Mark 9:14-onwards, which show Jesus performing exorcism on a boy.

Questions That Christians Need to Answer
1)Why did Jesus say that no sign will be given to his generation in Mark 8:11-13, but said that one sign would be given in Matthew 12:38-39? Weren't Mark's audience misled by Mark's Gospel and understood that Jesus told the Jews that he will give them no sign?

2)If you were successful at harmonizing the difficulty above, then how do you explain the fact that Jesus told the Jews that he would only give them ONE SIGN and that is the sign of Jonah, while he did perform other signs such as healing the blind and feeding thousands with a little amount of food?