Question: In the story of Joseph, is there a significance to why in 37:1 it’s Jacob but then later he referred to as Israel but then at the end of the story he is called Jacob again?
Answer: Israel was the name that God gave to Jacob back in Genesis 35:10 and in Genesis 35 both names are used interchangeably for Jacob just as you noticed in Genesis 37. I don’t believe there is any significance. He was known and referred to by two names.