Lightroom syncing in

Help! I am trying to sync my edits in Lightroom and it's not working. I edit the first image, then select the remaining images in the develop section and the rest of the images are a desaturated / strange edit - not even close to the edit that was copied. 

I have then tried to just simply copy and paste from one image to the next and this is also not working! When I click paste, the image just turns ours dull / desaturated again. 

any help would be greatly appreciated!