Opus Dei is an extreme reactionary group within the church. Leo XIII was a liberal pope responsible for the social doctrine of the church (this text).

https://en.m.wikipedia.org/wiki/Controversies_about_Opus_Dei

Personal experience: when I was in high school in my country there was a teacher who was in Opus Dei. He tried to recruit students by leaving them a letter and inviting them to a "scholarship". I got such a letter, I was so excited. The school found out about that and investigated. We're a mixed-race country. The Opus Dei teacher has invited exclusively white students. He had invited top students #2 to #4 in my class by grade, but not #1, who was black.