You’ll need to change:
.sticky-center
.sticky-grid
Set the flex alignment to “top” on these to eliminate the space.
You’ll then need to change the sticky offset to accommodate the depth of your fixed navigation
I never use the larger breakpoints. I can achieve all of the design treatments using the base breakpoint. Adding the larger breaks does’t help you with this design and it actually ends up causing more headaches. My settings below are done from the base breakpoint.
I personally avoid using the Grid layout function unless it’s mandatory to achieve something, which is rare… usually with CMS collection items. Instead, I use Flexbox with percentages.
Set the image fit to “cover” - this will fill the space but some cropping of your image will occur. I’ll usually adjust an image like this in Photoshop to accommodate cropping if it’s an issue.