That's because anchor holds objects to a relative position based on different resolutions.
This is mainly used for cross device or resolution of games. it's not really used to for placing objects on to the side.
So if you have an object that is 100px from the LEFT and TOP. Then it should remain 100px from the LEFT and TOP on all resolutions. This also holds true for RIGHT and BOTTOM which I find will be more influenced by different resolution sizes.