I was having the same exact issue and it was driving me CRAZY!!!!! I got online with two different techs, and neither knew anything about photoshop and couldn't help at all. Everyone wants to seem to blame the image itself, but it's just something about the default settings with CC it seems.
I was only have issues when the photo was zoomed OUT underneath 30%, but it was clear when zoomed IN above that. However, being so zoomed in made it impossible to see how the changes I was making during my editing process effected the photo as a whole. It was infuriating.
After trying a million different things, what seemed to work for me was changing my cache levels and checking the "Open GL". 
I had no idea why this might effect my photos so I didn't even think to check the cache levels. My friends Michael and Edita both helped me figure it out. According to Michael, when the image is opened it stores different sizes of the rendered image. I had mine set to only record/keep 1 cache level. Raising this allowed my photoshop to retain enough information to keep the photo accurate at any percentage.
I don't know enough about the software to clearly explain why this worked for me, but it did. Lets see if it works for anyone else!