Heavy Attacks Don't Proc Status

[devox15]

On Kogake Prime, I'm using the heavy attack with 100% status chance and it doesn't proc status hardly ever. This can be hard to see because the associated radial attack does to a lesser degree, but the leg swing itself, which does most of the damage, is not. 

A similar issue is occuring with Skiajati, where I always get the forced slash proc but can never proc anything else with the heavy.