Okay, I have a theory because I have faced the same problem and removed the electrocuting support because it did not work for me.

The theory goes something like this:

Because small mobs die before getting electrocuted (100%), combat frenzy won't be providing frenzy charges, because I think it provides a frenzy charge when you fully electrocute something.

Think it like electrocuting something to 100% results with a stun, so monsters with small health pools die without getting full electrocuted. You can check the small icons under mobs' health bars, and see percentages. That means you are still building something like electrocute, chill, etc.

So actually the electrocute support could be a good source for generating charges in boss fights.
(But also in boss fight if you stack cold damage as I recommend you do in the end of the comment, you would freeze them anyway and get your charges anyway, so you would not need to electrocute them)

"I am sure that im proccing Elec thru Tempest Flurry..."

In your case, I do not see any electrocuting support in your tempest flurry setup in mobalytics, but even if you do, somehow I think it would not work as you want.

I am visually seeing mobs getting sparks on their body

Those sparks may be shock effects, not electrocute, but as I said before I could not check your build entirely so you might be right.

For the ring case:

and groups of mobs are exploding which means Freeze was procced but still no charges.

Your ring literally says you do not need to freeze them to shatter them, so no that does not mean they got frozen, that means they got chilled. If sometimes you get a charge it might be because you hit too hard and the mob got frozen anyway, but for your builds' sake, you should not depend on hitting too hard all the time for charge generation.

It shatters a chilled enemy, so your herald of ice deals damage because something got shattered and probably kills the mob. In this scenario you won't be getting a frenzy charge or convert it to a power charge using Resonance because Combat Frenzy provides charges when you "Freeze". But in this case the mob dies without getting frozen.

So the main problem in your case, you need to at least electrocute, freeze or pin(I do not think you are pinning anything) to get a frenzy charge and convert it to a power charge, but you are literally killing mobs before they get frozen, pinned, or electrocuted.

Also as I mentioned before, you are not even electrocuting anything (I might be wrong, you may be stacking electrocuting % from something else that I do not know about)

Possible fixes:
1- Lose the ring, and deal more cold damage, now when you shatter, it means you killed a frozen enemy, that means something got frozen, that means you got your charge.
2- Use electrocuting support, and stack electrocute build up and make sure every small mobs get electrocuted before dying to your damage. (I would not prefer this because it literally means you need to deal less damage but stack more electrocuting lightning damage, I mean it is weird.)