Orb of Storms doesn't trigger secondary effect on Arc

I have been playing a Sorceress with a Lightning focused build and I noticed that when placing Orb of Storms down it triggers it's secondary ability of firing off additional bolts of lightning when Spark is cast in its radius but after swapping to Arc as my primary damage dealing skill I noticed that Orb of Storms quit triggered extra lightning bolts on the cast of Arc

I want to second this. I use arc and don't notice extra casts.

I can also confirm that Arc is not triggering Orb of Storms additional bolts.