Note the context. Immediately preceding this block of discourse is the block about them being slave to sin in which Jesus can free them.
See What does "free" eleutheroi mean in "you will be free indeed." John 8:36?
In the block of 8:44, Jesus was not denying that they were physical decedents of Abraham, but that they were not spiritual decedents of Abraham and previously labeled slaves to sin. It was a choice in that they were responsible for their condition and especially because Jesus was about to provide a way out of their condition.
39 They answered him, “Abraham is our father.” Jesus said to them, “If you were Abraham’s children, you would be doing the works Abraham did, 40 but now you seek to kill me, a man who has told you the truth that I heard from God. This is not what Abraham did. 41 You are doing the works your father did.” They said to him, “We were not born of sexual immorality. We have one Father—even God.” 42 Jesus said to them, “If God were your Father, you would love me, for I came from God and I am here. I came not of my own accord, but he sent me. 43 Why do you not understand what I say? It is because you cannot bear to hear my word. 44 You are of your father the devil, and your will is to do your father’s desires. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he lies, he speaks out of his own character, for he is a liar and the father of lies. 45 But because I tell the truth, you do not believe me. 46 Which one of you convicts me of sin? If I tell the truth, why do you not believe me? 47 Whoever is of God hears the words of God. The reason why you do not hear them is that you are not of God.”
(John 8:39–47, ESV)
Following this is the "before Abraham was, I am" block. In John 9 is the healing of the man born blind. They had a choice in how they interpreted this miracle.
And they reviled him, saying, “You are his disciple, but we are disciples of Moses. 29 We know that God has spoken to Moses, but as for this man, we do not know where he comes from.” 30 The man answered, “Why, this is an amazing thing! You do not know where he comes from, and yet he opened my eyes. 31 We know that God does not listen to sinners, but if anyone is a worshiper of God and does his will, God listens to him. 32 Never since the world began has it been heard that anyone opened the eyes of a man born blind. 33 If this man were not from God, he could do nothing.” 34 They answered him, “You were born in utter sin, and would you teach us?” And they cast him out.
(John 9:28–34, ESV)
In John 11 after Lazarus was dead for four days, Jesus raised him from the dead. The had another choice.
Many of the Jews therefore, who had come with Mary and had seen what he did, believed in him, 46 but some of them went to the Pharisees and told them what Jesus had done. 47 So the chief priests and the Pharisees gathered the council and said, “What are we to do? For this man performs many signs. 48 If we let him go on like this, everyone will believe in him, and the Romans will come and take away both our place and our nation.” 49 But one of them, Caiaphas, who was high priest that year, said to them, “You know nothing at all. 50 Nor do you understand that it is better for you that one man should die for the people, not that the whole nation should perish.” 51 He did not say this of his own accord, but being high priest that year he prophesied that Jesus would die for the nation, 52 and not for the nation only, but also to gather into one the children of God who are scattered abroad. 53 So from that day on they made plans to put him to death.
(John 11:45–53, ESV)
Some of the Pharisees did follow Christ (not to mention later Paul did).
Nicodemus, who had gone to him before, and who was one of them, said to them, 51 “Does our law judge a man without first giving him a hearing and learning what he does?” 52 They replied, “Are you from Galilee too? Search and see that no prophet arises from Galilee.”
(John 7:50–52, ESV)
After these things Joseph of Arimathea, who was a disciple of Jesus, but secretly for fear of the Jews, asked Pilate that he might take away the body of Jesus, and Pilate gave him permission. So he came and took away his body. 39 Nicodemus also, who earlier had come to Jesus by night, came bringing a mixture of myrrh and aloes, about seventy-five pounds in weight. 40 So they took the body of Jesus and bound it in linen cloths with the spices, as is the burial custom of the Jews.
(John 19:38–40, ESV)
Those who did not believe were blinded by their own will.
How is it that this man has learning, when he has never studied?” 16 So Jesus answered them, “My teaching is not mine, but his who sent me. 17 If anyone’s will is to do God’s will, he will know whether the teaching is from God or whether I am speaking on my own authority.
(John 7:15–17, ESV)