It was set for the widest exposure because I have a group of friends coming in to beta read it. I also checked free and premium.
I see it in those groups. It looks like the last chapter was published on November 13 (Chapter 26) so the sorting is near that date (there's actually a bug in sorting so it should be that date but is actually November 16). Did you publish a more recent chapter?
Changing the publishing settings doesn't change the date or pop it back to the top of the list.
It's the actual first-time publishing of the content that sets where on the lists it displays.
I see it on the Read - Groups (at top of page click Read and then Groups Content) list as well as the Free eBooks list:
http://www.thenextbigwriter.com/free-ebooks
Sol