Attempt to reduce Min Height on single breakpoint.
This is probably a bug in 2017.1. I suggest defining your site with a minimum page height when you get started with the site, and not touching it thereon. From what I know, any change to height will be reflected across other breakpoints as well.
I generally set a height of about 800px on each breakpoint when I create a new file.
Muse changes the min height based on the inserted page content.
I was trying to set it back to 800px to troubleshoot a huge gap between the bottom of the content and the footer on some pages.
I always check for elements that might off the Canvas or transparent that could be causing the gap. No elements present.
I have been building a new website from scratch (not this website) with Muse 2018 as my preparation for updating fully to Muse 2018.
Similar problem, however in 2018, in some cases, the Design View does not show the gap, but it is present in Preview in Browser.
Many apologies to find you in this trouble.
However, would you mind sharing your .muse file with us so that we can investigate and try fixing it?
For sharing the file you can follow the steps explained here - https://forums.adobe.com/docs/DOC-8652 and send the link to me in a private message.
For doing a private message hover the mouse on my picture and click "message".
Thanks. This is the same file I already sent you.