Stop nginx reverse proxy from redirecting

There are several similar questions but I haven't been able to figure out how to fix my problem.

I am running an instance of nginx on port 80 which acts as a reverse proxy for some other instances of nginx (which are reverse proxying for gunicorn running different instances of a django application.)

When I navigate to gaiadev1/, it works. when I login, a redirect occurs which sends the application to gaiadev:8080. I want to stop this redirect from occurring, but I'm not sure how to.

Here is the conf for the proxy on port 80:

upstream gaiadev1 {
    server 127.0.0.1:8001;
    keepalive 32;
}
upstream gaiatest1 {
    server 127.0.0.1:9001;
    keepalive 32;
}
server {
    listen 80 default_server;
    listen [::]:80 default_server ipv6only=on;

    server_name gaiadev1;

    location / {
        proxy_pass http://gaiadev1;
    }
}

server {
    listen 80;
    listen [::]:80;

    server_name gaiatest1;

    location / {
        proxy_pass http://gaiatest1;
    }
}

and here is the conf for the nginx instances running the applications:

upstream gaia {
    server %s;
    keepalive 32;
}

server {
    listen %s default_server;
    listen [::]:%s default_server ipv6only=on;

    # Make site accessible from http://localhost/
    server_name localhost;


    location /static/ {
        root /gaia;
        index index.html;
    }
    location / {
        proxy_pass http://gaia;
    }
}

After some fumbling around with the nginx documentation, I found a setting for proxy_redirect which solves the issue.

location / {
    proxy_pass http://gaiatest1;
    proxy_redirect http://$proxy_host:9001 http://$host:80;
}