Sierran Inheritance doesn't always invert chill at 1 Elemental Ailment Threshold

If you are using Chaos Inoculation with no sources of ailment threshold, you will have an Elemental Ailment Threshold of 1. While applying self chill with Shackles of the Wretched Sierran Inheritance will sometimes not invert the chill.

Tested with Iceshot using Cadiros Gambit.

Was also not getting reverse chill effect on my stormweaver with heavy snows. As i was chilling large packs and rares, there would be a certain chill that would override the 2 reflected chills that would not be reversed.. it would slow me down for a long duration, this chill debuff did not have a timer.

Does anyone know if this is a bug? Im having the same issue and this is the only place Ive seen anything about it.