Ghost Dance 40% attack/cast speed buff is bugged

It's kind of hard to replicate this bug, and I can't figure out the exact cause.

The bug is that sometimes I'm not granted the 40% atk/cast speed despite ES recharge starting recently.

My setup is that I'm using Eldrich Battery, and have 32 maximum ES. I have Abyssal Cry level 1 linked to Void Manipulation giving it a mana cost of 31 mana. So when I cast Abyssal Cry the first time, it works as intended and once my ES starts recharging, I get the attack/cast speed bonus. But if I spam my Abyssal Cry and cast it again as soon as my ES has regenerated to 31/32, most of the time I don't get the attack/cast speed buff once my ES starts recharging the second time.

I think its most likely a timing issue, where if ES starts recharging in a certain window then it isn't registered and thus doesn't grant the buff.

Here's a demonstration of the bug:

https://gfycat.com/VagueDirtyArgentineruddyduck

If you need any more details let me know, thanks.

It might be waiting for the last recharge to end and the new recharge start does not end it so it still thinks it is that instance.
Does it do the same if you allow your ES to totally fill?

Yes it does happen if I allow my ES to totally fill as well. But not 100% of the time, thats the peculiar part. Like just now I tested it with 136 total ES, enough that my pool fully refills before the 4s cooldown on the Warcry is up. Bug appeared to happen still, though as in all scenarios, it doesn't happen 100% of the time, if even 20%.

From sitting in my hideout for a solid hour and just trying different ways to reproduce the bug, it seems to just be a timing thing. It's like there's some small window where if the recharge happens, it isn't recognised.