I’m doing many things at once. Tried to redo my research, here’s a few links abut Khazars, who came from what is now Khazakstan. What I read and can’t find the exact article now, but these links also give info, that they were traders, came into contact with Muslims, Christians, and Jews, and eventually many of them converted to each of those religions. Intermarriage with existing members of those three religions occured. “Jewish” can mean one who observes Jewish religious practices and beliefs, or one born into a Jewish line. Studies were done on European Jews (can’t retrace my research right now) and found they all or vast majority had some ethnic Jewish ancestry.
https://www.britannica.com/topic/Khazar