Hi there,
thats really tricky to do.
The issue is related to Aspect Ratio.
The ratio of the image is different to the Container Block it is applied to.
If you want an image to scale proportionally on all screen sizes then a) it needs to be full width and b) its height must match the images aspect ration, using the Minimum Height and vw
( viewport width ) values.
Alternatively:
Use one Container Block with no Padding, to add your background image.
Then inside that Block add 3 more container blocks, one for the grid, one for the full width bar, and one for the footer image area. You can then control the spacing as you need.