I think we can only make an educated guess from CNN article

From the Catholic News Agency article (linked below):

The conflict between the school and the archdiocese began with an archdiocesan request that the contract of a teacher who is in a same-sex marriage not be renewed.

The school became aware of the teacher's same-sex marriage in the summer of 2017, according to a June 20 statement from Fr. Brian Paulson, SJ, head of the Jesuits' Midwest Province.

Paulson said the archdiocese requested “two years ago that Brebeuf Jesuit not renew this teacher’s contract because this teacher’s marital status does not conform to church doctrine.”

Click here for link at https://www.catholicnewsagency.com/news/indianapolis-archbis