Cliffhanger penance for Psykers

Hello. Cliffhanger penance says i need to push 7 enemies and kill them within 2 seconds i think as a psyker. Im sure im doing it correct but its stuck since beta on 4 out of 7 kills.

This is “seven enemies within two seconds” not… “they need to die in two seconds”. It’s stuck on four because you’ve never pushed more than four enemies to their deaths in two seconds, no?