Not sure where it fits in the bug/problem/whatever categories, but I ran into an issue where it was showing the folders but not the report files from the web browser after I upgraded from 5.0 .net to 5.5 .net (non core) with an Azure app service switcharoo.

The fix for it was to clear the cache of the browser, and then it started working properly. It worked great when I used the back end URL but failed with the Alias re-point.