Question Monitor corners turn dim after a second

[Takku0223]

Hello again wonderfull people of tom's hardware forum,

Like the title suggest monitor corners turn dim after a second, it only happens in the right top and bottom corner and is like a triangle of what seems no backlight.
This happens in all picture modes except for Eco mode, I already figured the thing is broken since it doesnt happen on other screens i plug in but I wonder why this doesn't happen in eco mode, any ideas?

 

[Lutfij]

Can you please add a video to elaborate on the issue you're facing? Perhaps the panel is drawing less power when in said mode. Also, can you mention the make and model of your monitor?