I’ve been dealing with this same question lately, too. A lot of Jews will say Jesus “does not fit the genealogical requirements” because the Blessed Virgin was descended from Nathan, David’s other son (because Luke’s genealogy is of the Blessed Virgin and Matthew’s is of Joseph), and the Messiah supposedly must be descended from King Solomon, rather than Nathan (for which they cite 2 Samuel 7:14; 1 Chronicles 17:11-14, 22:7-10, 28:4-6). They also claim that there is no Biblical basis for the idea of a father passing on his tribal line by adoption, as is the case with Jesus and Joseph (who was not Jesus’ real father, yet descended from Solomon).
Another theory is Luke’s genealogy is also that of St. Joseph’s.
His family situation, it is believed, involved a Levirate marriage so he had a biological father and a legal father, who was dead.
From the Catholic Encyclopedia:
"According to the latter, Estha married Mathan, a descendant of David through Solomon, and became the mother of Jacob; after Mathan’s death she took for her second husband Mathat, a descendent of David through Nathan, and by him became the mother of Heli. Jacob and Heli were, therefore, uterine brothers. Heli married, but died without offspring; his widow, therefore, became the levirate wife of Jacob, and gave birth to Joseph, who was the carnal son of Jacob, but the legal son of Heli, thus combining in his person two lineages of David’s descendants."
You can search “Genealogy of Our Lord” to learn more.
Pax et bonum.