Impact Shockwave and Stomping Ground Support Gems Not Working Correctly

Tested Impact Shockwave socketed on Siphoning Strike, also had Overpower support gem socketed. No aftershock was ever created when I Heavy Stunned an enemy.

Tested Stomping Ground socketed on Vaulting Impact, also had Magnified Effect socketed on Vaulting Impact. No Shockwave was ever created when using Vaulting Impact.

Thank you.