There was a recent change making Warrior Monks attack in combat, to apply the buff. It is reasonable to some degree, but not really. Their damage is awful and you’d rather have them heal your units (that is kind of the point of a religious combat unit). I could get around this usually by toggling off Auto heal initially, letting them attack–then turning it back on in combat to make them heal.
Now however, it is impossible. They will only attack and to heal in combat, you need to specifically select them and right click the units you want to heal. Bad solution, and this is overall a massive nerf.