I certainly have not intentionally set up a firewall? This is a pretty new computer too so I'd remember if I had

I am trying to set up FAF on Ubuntu with an install through Steam.

I've followed all of the instructions at this link: https://github.com/FAForever/faf-linux/blob/master/README.md. All packages and the Steam install have gone perfectly smoothly, but on step 5 things all break.

After the ./setup.sh, I try ./run.sh and log in. The log in takes me to the Firefox, where I log into my FAF account, and it asks for permissions. Clicking "Authorize", I get errors both in the browser and the FAF client.

In Firefox, the error is "Unable to connect Firefox can’t establish a connection to the server at 127.0.0.1:42313." (The port changes each time.) And in the FAF client, I get "Uh oh! Error occured during login" with a Java traceback like this:

Client Version: 2024.6.2
java.lang.IllegalStateException: Could not extract value with pattern 'code=([^ &]+)' from: <gibberish...>
	at com.faforever.client.login.OAuthValuesReceiver.extractValue(OAuthValuesReceiver.java:145)
	at com.faforever.client.login.OAuthValuesReceiver.readValues(OAuthValuesReceiver.java:137)
	at com.faforever.client.login.OAuthValuesReceiver.readValues
        (etc)

What gives? Not sure if my browser privacy settings are breaking the login somehow? Trying "Play Offline" in the FAF client does not seem to work either, failing with an error that there is no launchwrapper, or no faforever/bin in my user profile directory. I've tried a few variations, like running ./set-client-paths.sh first, and nothing works.