Doctrinal unity is different from impeccability. Christ's Church is a Church of sinners.
It’s one thing for the church to be made up of sinners. It’s quite another for the church to KNOW leaders in the church are not following church doctrines and ignore the problem.
Setting doctrine and then ignoring it for the sake of unity is no doctrine at all.
Church leaders are rarely punished (and in some cases encouraged) for espousing their own theology contrary to the Vatican's position. The Vatican's position is typically to turn a blind eye to the matter.