LG 5k image retention normal

Hello,

In January I received a LG 5k ultra fine and a MacBook Pro 15". I am very happy with the image quality, but these days when using for example Pages or Safari and wiping to dashboard, the display has signs of image retention and I can clearly see the pattern of used windows an text shades. This effects occurs very quickly, it just needs to place a few minutes a static image/window on the screen and after it on some backgrounds I can clearly see the image retention, which disappears in less than a minute. This effect itself doesn't bother me too much, but I am afraid that this could be a defect, that could get worse with time.

So what do you think? Is this a inherent behaviour of this kind of technology or could this be defect, so that it needs to be changed?

Best regards