Hi Kailee,
The reason is the default S3 url is with http, not https
then you would need to use our http site, not https site to visualize your files,
http://epigenomegateway.wustl.edu/browser/, notice that is http://, not https if you setup https on your hosting, you can use the https site
see the screenshot with our example file showing on the http site, let me know if you still have issues.
thank you!