Scavenged Plating - Not working

I recently got a body armour w/ +spirit which now allows me to use a third buff. I am currently using Herald of Ash, Overwhelming Pressence and now with enough spirit I am using Scavenged Plating. However, scavenged plating is not collecting stacks, nor is it increasing my armour. I triple checked everything and I have enough stats to use them. I removed herald of ash and overwhelming pressence to and just had Sacvenged Plating equipped and thought that might fix it, but still nothing. I tried restarting, multiple times, and still it is not working.

Any advice? Or thoughts on what I need to do to fix this?

PS...before I was running Overwhelming Pressence and Scavenged Plating (about two weeks ago) and it was working fine. I could see the buff stacking and my character screen would show the increase in armour.