Kindred ulti BUG

Kindred's ulti is supposed to keep the allies within at a minimum HP , but when they take damage that would put them below that minimum he negates all of the dmg instead of putting that character at that minimum and negating the rest of the damage. I believe this is what happened to me in a match that i have lost because my MF'ult would not damage to anyone that was inside Kindred's ult.I'm not sure if this is a bug with the interaction between MF and Kindred's ultis but i've seen it happen a couple of times with some other abilities too.