In the Genesis Settings I put the max size 400 x 920.
You need images at least that big for the slider to work correctly.
Max size sounds like that’s the maximum size.
In any case, I have also made some slides 1250 x 430 and they are also positioned lower than center, and look like they are expanded. Nothing looks right in the slider.
Clarification – All of the images need to be at least as big as the maximum size setting for the slider. The setting is for the maximum size of the slider not the max size for images.
Once you have images that are large enough contact your theme support if it’s still not displaying the same as the theme demo.