Morior invictus 5 sockets corruption does not work

On item it states that it gives stats per socket filled.
Though on my char screen it gives items for 4 sockets filled, my morior invictus is 5 sockets

I have the same problem. My Morior Invictus is corrupted with 5 sockets, but only give the effect of 4 sockets even when all 5 are filled.
My used sockets are: 3x Soul core of Jiquani, 1x Craiceann's Rune of Warding and 1x Amanamu's Gaze.

https://www.pathofexile.com/forum/view-thread/3890596/page/1

The problem isn't the 5th socket, it's the abyssal eye. Check my post for info.