Ethics is a topic which is discussable but only meaningful when placed in the context of "virtues". Hence, virtue-based ethics.
Well-defined and well-discussed aspect of moral theology, at least in Catholic circles.
Try this. Look up ethics in Wikipedia and see how many times God or scripture is referenced as a source for defining right and wrong. Now look up morals and do the same.
Do this one. When sitting in any ethics training in college, government or corporate America, listen carefully and again determine what is referenced as the source for defining right and wrong. With ethics they will mention laws, policies and secular philosophers/philosophy. When morals are mentioned, outside of ethics training, you'll hear references to God.
Bottom line: in colloquial language (except in those cases as you mention, and there are some others- I went to a Jesuit college), the nuance difference between morals and ethics is that ethics is the teaching of right and wrong without any mention of God, the Bible, Jesus, etc.