Icefang Orbit doesn't apply chill for all sources of damage taken

I'm attempting a self chill build, but ran into a wall when I realised that Icefang is refusing to apply chill when I'm damaged by self-inflicted sources such as Heartbound Loop, or Apep's Supremacy.

I have an elemental ailment of 1, so all hits should be chilling me while I'm poisoned, but despite taking large hits while poisoned from either Apep's or Heartbound Loop, no chill is applied.

If I go into a map, however, all monster damage that hits me while I'm poisoned applies chill, so it's clearly working for some damage sources.

The item's description is clear that "All Damage taken from Hits" contributes, but it appears to exclude sources that come from non-mobs.


More info:

I am self poisoning using Apep's supremacy and Infinite Pursuit to get over 50% chance to be poisoned. Using a relatively high cast speed ability causes me to take damage proportional to the mana cost, n times per second, applying poison ~ half of the hits, resulting in me being consistently poisoned.

This is where Icefang comes into play. Since Apep's is poisoning me with its hits, the damage clearly does count as a physical hit or I wouldn't be poisoned.
Therefore, the same physical hits that are keeping me poisoned should also inflict chill magnitude on me because of Icefang, especially since I've reduced my elemental ailment threshold to 1. However, this is where it's failing and I'm not getting chilled by these hits, only if I get attacked by mob hits.

I also tested with Heartbound Loop to take phys damage on minion death. Again, it applied poison, but while poisoned I did not become chilled by subsequent minion deaths.

Edit: Also tested with volatility and it didn't appear to chill me either while I was poisoned.

ran into this as well, visibility bump
can self poison via scold's, but can't apply chill via scold's or volatility
while using sierran + icefang + apep's