It wasn't HoPF the was nerfed directly. It was the delay between throwing a nade, and the next one beginning to charge. That's why you need gift of the sun.
English
-
That's literally what the exotic perk is on hopf, I've tested it out and you get 1 more grenade with it. I use double fusions btw.
-
HoPF still makes the recharge faster, on both nade and melee. It sounds like you tested either without radiant will, or without maxed discipline. Maybe even without either.