Volkuur's Guidance - Gaining Virulence while having 100% fire damage conversion

Main setup is

- Ngamahu, Flame's Advance for 50% damage conversion to fire
- Avatar of fire for 50% damage conversion to fire, deal no non fire damage

- Gloves: Volkuur's Guidance - your fire damage can poison
- Herald of agony
- Cyclone + poison support (tooltip shows 80% chance to poison)

With the above setup I get no virulence stacks. :-)

Unchecking Avatar of fire solves this problem. So even when my fire damage can poison it didn`t when I deal no non fire damage.

Bug or am I missing some game mechanics?

thx for any help
Ash

Check https://www.pathofexile.com/forum/view-thread/2271832.

Thx