Self-hosted can't upload, visit most pages

[WorldsEndless]

We are trying to host the latest version (downloaded from "releases" this morning, 2.4 M1) and it won't work. We get the splash page, but trying to use any corpus (including the built-in ones) fails. Trying to upload a corpus results in a never-ending spinner, while selecting something default (e.g. Jane Austen) pops up with an error "Failed Attempt to Create a Corpus". Many of the links for help also fail. I wonder if these could all be part of the same problem: half the links (and presumably the corpus creation/upload stuff) is trying to utilize addresses like "http://127.0.0.1:8888/docs/#!/guide/corpuscreator", which obviously fails for a real server that isn't localhost. Something in the code is using :, apparently, rather than respecting our real server (voyant.byu.edu). We've been having this problem for months, but now it's getting urgent.

If the problem is on our end, please let me know what I need to change in server-settings.txt or something else; right now we've stayed away from touching anything other than the port, which we are accessing in Apache via a ReverseProxy. My suspicion, though, is that the code mis-constructing paths.

[WorldsEndless]

More corroborating evidence: my network tools reveal that it is trying to post like "POST
http://127.0.0.1:8888/trombone", which should be something like POST
http://voyant.byu.edu/trombone