Twister and whirling slash don't proc Poison support gem

Using either twister (spear ability) or whirling slash, neither of these proc poison support gem.

Edit:
Neither is rake. I can't see why any of these wouldn't work with the support, they both (not including rake) work with bleed support. What's the difference in how they proc...

Edit 2:
I'm dumb, using brutality support. Though thinking of it, should that really prevent the poison proc? All it says is the ability won't do chaos damage, poison being procced by it seems like a separate thing. Description isn't clear if this is how it's supposed to work