Islam subsribes to a gnostic Jesus. Gnosticism was very popular in the aramaic speaking regions in what is now Iraq and Syria. It’s probable the koran borrowed heavily from th religious millieu going on in that region. Many of the stories in the koran would be seen as plagiarism in a modern context. I studied syriac in a previous life.
Most of Muhammed’s understanding of Christianity and biblical stories came from Waraqah ibn Nawfal, a former Catholic priest wannabe for one of the desert sects who had some really strange beliefs about biblical patriarchs. Even Wikipedia admits that “Waraqah is also important because he plays a role in legitimizing Muhammad’s revelation.”