Full width footer not working

I have a full-width footer on my website but for some reason, it won’t extend to the full width on this product page.

If I add additional CSS to extend it, it will only work if I change the height to 100px rather than changing the width. Also, it will only extend half of the footer, it won’t extend the nav menu area within the footer.

I am pretty stuck with this, it is probably glaringly obvious but any help would be appreciated.