Moving this discussion to the Photoshop Express for iOS forum.
Can you give us a little more information about your situation? What do you mean by "synced" your photos? We dont really have this functionality in photoshop express, you can open a photo for editing, but we dont have sync functionality. Im a bit puzzled by the disappearance of photos, on iOS, the operating system does not give an app the ability to delete photos from the phone so im not sure how this happened. Do you have any more info on what happened leading up to them being missing? Hope we can help resolve this!
Just wanted to check if you were able to figure out the reason of your photo synch issue.
I had the same thing happen but it was when I upgraded from the iPhone 5 to the iPhone 6. Photos I had been saving since the iPhone 4 are no longer in the cc library
I have been afraid to use the app ever since