Envenom not triggering with spark

Envenom is also not working for Fireball even though the skill details say Chance to Poison 50%. I can confirm that Fireball does "hit" since Bludgeon (another proc on hit support) procs with it.

New here. I did some testing as a Storm-Weaver.

I notice that Envenom and Lacerate doesn't work with most "Spells" so I went and tested it out on Bone Cage since I used that to stop enemy movement.

Come to find out "Hit" is not what we think it is. If you hold Alt over the word Hit on your support gem it will say the following: "Any damage that isn't damage over time is Hit Damage".

That means most or all Elemental spells will not work as they are all DOT abilities.

In the poison tooltip, Poison states that it scales magnitude off of physical or chaos damage. I'd assume a 0 magnitude poison proc doesn't switch the enemy bar green, so this won't work on anything doesn't deal physical or chaos damage, which is achievable via shenanigans on any projectile, so technically envenom could work on them, but it won't without deliberate effort on anythning that's dealing purely elemental damage, e.g. frostbolt, fireball, shock, etc.