OK so this is very strange. There are 3 carousels on the home page and they are working this morning. As of last night they were still not working.
So I created a new page to test and I was still having the issue there. Then I cleared both WordPress cache and browser cache, and now the new page is also working. Strange. Now every carousel I add works. How could it be a caching issue if it was happening on a new page I just created?
This is the test page: http://b7a.131.myftpupload.com/carousel-test/
Anyway, problem seems to be solved.