This question has been posed a couple of times with no real correct answer or explanation given. When publishing the site, a big area of white browser space appears below the footer/bottom of the page. I've tried every single recommendation that's been given, unchecked sticky footer, checked to see if there are any invisible elements below the footer (which there aren't), made sure page is set to correct min-height etc, etc, etc, all to no avail. It's most noticeable on phones and tablets as the page goes flying up into the ether.
This is the site in question, it's in beta stage pending client approval. Like it or not, this could a bug that needs to be rectified in what will be 2018.1 I guess,
I bet, this was explained many times here. I see at least two threads here, actually on the first page of this forum, dealing with this layout issue – and these questions have been solved!
Here again my suggestion: Share a .muse file of your page (via Dropbox, CC Files, …), containing only one page and as less elements as possible. Please follow these instructions: https://forums.adobe.com/docs/DOC-8652 Then we will have a closer look.
I am quite confident, that we’ll find a solution.