Issue with the new anchoring system

[jeldrez]

I'm working with the new anchoring system to stretch the background to match screen size, but something weird is happening. If I tested in the editor there's no issue until I click play and the background shrink to his minimum size. You can see in the image attached the anchors goes far away from the screen and I don't know why. I tried anchoring to the UIRoot and UIPanel and it happens the same.

The hierarchy is this:
UIRoot
--GameObject (UIWindow custom script)
----UIPanel
------ UIAnchor/Center (yeah, I know is deprecated)
--------UIWidgets

At the top of the image you can see how far goes the anchoring and at the bottom the screen for reference.

*EDIT*
The only way the background keep the shape is keeping the target at center, is not what I want but at least didn't break.

What could be?

[ArenMook]

Most common cause of stuff like this: having multiple cameras drawing the UI layer.

[jeldrez]

At the end I notice that programmers changed the UIPanel script. He added new behaviors changing how it works the update. This panel was not updating, making anchors fails.

Thanks anyway