Strike skill target # additional enemy don't give Endurance charge from Passive "Smashing strikes"

Hello. Have a problem with mechanic.

Strike skill target # additional enemy don't give Endurance charge from Passive "Smashing strikes" (from the left end, Staff mastery). I use Lightning Strikes and my attack strike with lightning from the sky. If I use "Strike skill target # additional enemy", in range of my melee strike I could strike some more enemy (with my lightning melee attack), and based on this logic I must have Endurance charges from this targets. But with this skill + Passive I could only generate Endurance charges only when I stay on the mob, only from "mother" strike, any other won't work.

Thanks for help!