I just upgraded the Sydney Theme to 1.37. Immediately I noticed the full page slider pictures on several of the sliders overlaid a smaller copy of the picture. I am (and have been with no issues) using a child theme, PHP 7, and WP 4.7.3. I activated the main theme to see if the problem duplicated. It did not. I reactivated the child theme and the problem was still there.
The website url is https://www.tnalpha.com You should see the effect on the second slide of the front page slider.
PLease let me know if this is something easily fixable.
Bryce (aka Wordjunky)