Hi Jean,
Thank you for the credentials, I kind of spend more time than I should investigating this issue, but its kind of hard because the site is not giving any errors. At first, I suspect that this issue is related to a caching because of the weird things going on the site, so I did make sure to clear and deactivate the caching plugins (WP Super Cache & Jetpack). Although clearing cache and deactivating Jetpack solve some of the warnings on the console, it did not address the footer issue. I did proceed to check some other things on the site, but no luck.
When I was about to give up, I decided to take one last look at the header (does not make sense, right?). But I found this one little issue, that last custom CSS block has no closing bracket, which messes up the other generated CSS when they merge on the frontend. Your footer should be fine now and clear your browser’s cache.
Sorry for the delay, hope this helps 
Cheers!