background images not aligning

Hello,
I have 3 sections, each section has a custom background I created in photoshop.
All 3 background images are the same size, and they have a colored section with clear borders around. All are the same size,

So I have section 1, 2, and 3 with the same background. But Highend changes the color squares in the background. All 3 sections have the same margin settings.

When I resize the browser % smaller, they all align however.

Please see attached pictures.