I AFKed at my raid farm for about an hour without getting bad omen once. I tried afking without the trident killer on and when I checked on the pillagers there, there were about twenty of them and none had banners. After, I went into a creative testing world, and not only did they not spawn with banners when I specifically summoned a captain/patrol leader, but they did not give off the bad omen effect when killed in survival. I had no idea this is a thing, and now my raid farm is practically useless until this is fixed.