Remove left/right padding from Gutenberg Cover Block image

Hi there, I'm using Gutenberg Cover block, to add a background image, and then add GenerateBlocks on top of this.

The problem is that I can't remove the left right padding, so the image aligns with the header and the footer.

https://imgur.com/XZkr789

Actually i can set the padding to zero, but the zero value does not apply after saving, even if the values are zero after reentering the customizer.

https://imgur.com/mX2AFTg
https://imgur.com/9FFY75m
https://imgur.com/G2DS8fg

On mobile the padding does not change when it is set to zero:
https://imgur.com/9FFY75m

Why does these settings apply, but then not, and how can I have my background image on my frontpage to fit into the container, to align header and footer without left/right padding both on desktop and mobile?

Thanks