Hey Alexis,
Something in the footer was corrupted and saving the footer again usually fixes this glitch. Resaving didn’t fix though and since your footer is just simple, you can recreate the footer like I did to fix. Please check your site now.
To perform your troubleshooting in the future for styling difference between the builder preview and the live page, you can create a test page and eliminate the header and footer by choosing a Page Template that has no Header and Footer like the Blank Container | No Header No Footer. If the issue’s fixed, that means the issue is either within the header or footer. You can then do the same procedure to narrow down where the issue is.
Once you’ve found where the issue is, you can further narrow down to the element level by duplicating the header/footer and removing elements in them one by one while checking the live page each time you do that. The last element you remove that fixes the issue contains the broken or corrupted builder data or custom code.
Hope that helps.