Adaptive Skin (notable skill) not working with converted damage and proc inconsistency

The Adaptive Skin node does not trigger from converted damage. I am playing a shaman with 5% of phys taken as each element, so it should give me +1 max fire/cold/light resistance anytime I am hit with a physical hit. It does not.

It will proc inconsistently when hit with just one type of elemental damage (tested with the cold spitters and with the fire explode from the log dudes), however. Even though I was getting hit many times with the cold projectile from spitters, the uptime was inconsistent (certainly should have been permanent as I was getting hit much more frequently than once per second).

Either the skill is bugged or needs to be reworded. Thank you.