Lately ive decided that want to change my background. So when I do after unlocking the screen it show the whole image then quickly resizes to half the image. What am I doing wrong here?
I havent had that problem. However.. I download the wallpapers I want to use (from zedge) but I go to the gallery and set the wallpaper from there. Try that and see if it makes a difference.
That's what I do. Most of my wallpapers are from Zedge. I always download them to my gallery, and set them from there on the phone settings menu. Never had a problem.
The simplest and best way to avoid issues with your wallpaper is to ensure they are made to the exact size of the screen; 1920 x 1080. If done properly, the wallpaper should as well weigh very little; 20-30k or so for a static background.
I have nova launcher but currently try not using it. I did for a bit a while ago then didn't use it. And I tried using the stock wallpapers it would show up when I unlock the screen then quickly go to half size again.