Frenzy of onslaught bugged

I'm a slayer charge stacker I can go up to 9 all charges actually and my frenzy of onslaught sacrifice only 3 charges(got 3 charges and sacrifice), i'v try with get some max frenzy on my tree and it does the same

I'm currently at 11 maximum power charges giving max 11 frenzy with badge of the brotherhood giving me 11 Endurance with the masterful form and Frenzy of onslaught It always remove my frenzy at 3 charges when I attack with it, I can get frenzy with other way and it always remove my frenzy when I hit with more than 3 charges.

With Ralakesh boots, maximum frenzy charges does not matter, only your current charges for the Onslaught portion. If you have 1 current charge and 9 maximum charges, when you hit it should consume the 1 charge and give you 1 second of Onslaught (or maybe 2, not sure if generate happens before consume). But it shouldn't be 9 seconds.

If you generate charges from other sources like your frenzy charge on kill, it doesn't matter and the next time you hit an enemy, all of your current charges will get consumed due to Ralakesh counting you as always maximum charges. You just keep the attack damage/speed scaling regardless of frenzy charge consumption since you're always counted as maximum.