Enhancement from Paragon Market providing no benefit

So I bought a Karma knockback protection enhancement from the Paragon Market. I slotted it, but I'm getting zero points of knockback protection according to my combat attributes monitor. It's also pretty obvious as my character flops around on the ground.

Known issue? Being worked on?

$1.25 for knockback protection is worth it to me, if it worked.

I'm apprehensive about purchasing other enhancements when this one doesn't work at all.

I will buy one and test tonight if nobody else does. Meanwhile you might wanna crosspost this to the i21 bug forums too.