Phasezerker Class Mod Bug

I’m using the Phasezerker class mod to maximize my Amara build damage by reducing the action skill cooldown as I use a weapon anointment that give 250% on phasecast skill use.

Expected Behavior
The Phasezerker class mod should give 10% cooldown rate increase per stack. I have a 10% cooldown rate reduction from guardian rank, 20% cooldown rate reduction from shield anointment, and another 5% from Restless passive ability. In addition, I have the Avatar passive ability, which allows me to build a lot of rush stacks whenever I cast phasecast, which in theory should allow me to achieve very low action skill cooldown.

Actual Behavior
When I respec my character build, I can achieve 5 second cooldown rate. When I use this in combat, sometimes it slows down to 6-7 seconds.
When I exit the game, or join another hosted game, I get 10+ second cooldown rate.
When I remove my Phasezerker class mod, I get the same 10+ second cooldown rate.
When I respec my character build, I can achieve 5 second cooldown rate again…


The lower cooldown after respec is from bug due to Topped Off Guardian perk. Quiting to main meny fixes it and cooldown is calculated properly.
Phasezerker provides 3% cooldown per stack iirc, the info on card isn’t correct.

So the higher cooldown rate is the correct behavior? As well as the item description not being correct.