You really need to investigate what Luther actually believed concerning Mary, from the source itself, not anti Catholic propaganda.
Whoever is weak in faith can utter no Hail Mary without danger to his salvation. (Sermon, March 11, 1523).Who possess a good (firm) faith, says the Hail Mary without danger! Our prayer should include the Mother of God.. .What the Hail Mary says is that all glory should be given to God, using these words: "Hail Mary, full of grace. The Lord is with thee; blessed art thou among women and blessed is the fruit of thy womb, Jesus Christ. Amen!" You see that these words are not concerned with prayer but purely with giving praise and honor.. .We can use the Hail Mary as a meditation in which we recite what grace God has given her. Second, we should add a wish that everyone may know and respect her...He who has no faith is advised to refrain from saying the Hail Mary. (Personal Prayer Book, 1522).
“It is an artcle of faith that Mary is the Mother of the Lord and still a virgin…Christ, we believe, came forth from a womb left perfectly intact.” (Works of Luther, V. 11, pp319-320; V. 6, p 510)
John Calvin: “there have been certain folk who have wished to suggest from this passage (Mt 1:25) that the Virgin Mary had other children than the Son of God, and that Joseph had then dwelt with her later; but what folly this is! For the gospel writer did not wish to record what happened afterwards; he simply wished to make clear Joseph’s obedience and to show also that Joseph had been well and truly assured that it was God who had sent His angel to Mary. He had therefore never dwelt with her nor had he shared her company…And besides this our Lord Jesus Christ is called the firstborn. This is not because there was a second or third, but because the gospel writer is paying regard to the precedence. Scripture speaks thus of naming the first-born whether or no there was any question of the second.” (Sermon on Matthew 1:22-25, published 1562)
Ulrich Zwingli: “I firmly believe that Mary, according to the words of the gospel as a pure Virgin brought forth for us the son of God and in childbirth and after childbirth forever remained a pure, intact Virgin.”.” (Zwingli Opera, Corpus Reformatorum, Berlin, 1905, in Evang. Luc., Op. comp., V6,1 P. 639
All three of the first reformers, Luther, Calvin, and Zwingli, accepted and defended this doctrine completely. So, if the Catholic Church believes in this doctrine and the reformers believed in this doctrine–by whose authority and when was this doctrine rejected by all the Protestant Churches?