I can't login to the web interface using the admin login. It's consistent in both Chrome and Edge. I logged in to the box as root, changed the admin password using the setup utility, tried again and it still doesn't work. Do I need to do anything for it to take effect?

The first thing that comes to mind is what port are you using? Other than that I don't know. What is actually happening? Are you sure you don't have a firewall getting in the way? What error messages are you getting?

To clarify there aren't any errors, it just reprompts for the login. Using the default port 444, pretty sure there isn't a firewall getting in the way.

That is usually an indication there is something wrong with the login. First read the signin dialog closely make sure you are really connecting. I think you are but that is the first thing to check just in case. Assuming you are using 'admin' for the username it sounds to me like there is something wrong with the password. Assuming you are trying with the same password each time, no mistypes, no unexpected caps, then the next place to check is the password you set. Reset the admin password carefully. I would use something simple that is hard to get wrong. If then you can sign in you know what the problem was and can reset it to something more suitable and secure. If it doesn't work then we'll have to try something else. I use ipfire, have for a couple of years, and have had no problems so I suspect it is something simple.