Problems with thumbnails with demo

Hello,

I’m customizing one of your demo “construction demo”, in the homepage I’m changing some images and so on but when I start edit the “our services” images I got this problem
https://gyazo.com/74828a2e920262b59d22adbca01cfc21
even if I rezise my modified image as the other ones ( 1732 × 1155 ) I always got this problem, image is bigger. When I add the image I tried every settings ( small, medium, big, etc ) but image is always like that.
What I’m doing wrong?

Thanks