Warlock question

There has been something driving me crazy.

My “Amplify Curse” has not been increasing the damage of “curse of agony”.

I use amplify curse and then cast curse of agony, I can see that the amplify curse buff is consumed, but the CoA does identical damage, no increase at all.

Can anyone tell me what I am missing here?

EDIT:
I figured it out on my own…

“amplify curse” is not functional on any classic realm at the moment, please submit a bug report.