At the very least, the idea of material heresy has never been condemned. Practically every Father who discusses the topic throughout the entirety of Church history has believed obstinacy is required to be a heretic.
St. Augustine, St. Jerome, and St. Cyril of Alexandria come to mind first as people who explicitly taught or explained heresy in this way. I am practically certain that St. Thomas Aquinas, St. Robert Bellarmine, and St. Alphonsus say so too. In fact, I'd be surprised if a single Father or Doctor of the Church ever taught the contrary.