Reverse proxy returning 307 (redirect) when it shouldn't be

I'm trying to setup a reverse proxy to an application that I'm building. The application is split into two docker images. First is a web UI, which can be reached via https://example.com/

The second docker image, has base addresses that I'm interested in. The first, is https://example.com/swagger and the second is https://example.com/api

When I navigate to example.com everything works as expected. I get the application front end. When I navigate to the swagger link, again everything is working just fine, I get the swagger page. the actual address is https://example.com/swagger/index.html

However, the third part of this is that the https://example.com/api is a Rest API that I want to access, when I try to make a call to this. Or more specifically, a POST request to https://example.com/api/Authentication/login

I get a 307 response from the server which redirects the call to http://actualserver.local:7066/api/Authentication/login

I don't understand why it's doing this, as it should be getting the information just as the swagger link is doing.

Here's my nginx.conf file that I'm using to run the reverse proxy

worker_processes 1;

events { worker_connections 1024; }

http {
    client_max_body_size 0;
    sendfile on;

    proxy_set_header   Host $host;
    proxy_set_header   X-Real-IP $remote_addr;
    proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header   X-Forwarded-Host $server_name;

    server {
        listen 80 default_server;

        server_name example.com;

#        location /.well-known/acme-challenge/ {
#            root /var/www/certbot;
#        }

        return 301 https://$host$request_uri;
    }

    server {
        listen 443 ssl http2;

        ssl_certificate     /etc/letsencrypt/live/example.com/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

        server_name     example.com;

        location /api {
            proxy_pass         http://actualserver.local:7066/api;
            proxy_set_header   Upgrade $http_upgrade;
            proxy_set_header   Connection "Upgrade";
            proxy_set_header   X-Forwarded-Proto https;
            proxy_redirect     off;
        }

        location /swagger {
            proxy_pass         http://actualserver.local:7066/swagger;
            proxy_set_header   Upgrade $http_upgrade;
            proxy_set_header   Connection "Upgrade";
            proxy_set_header   X-Forwarded-Proto https;
            proxy_redirect     off;
        }

        location / {
            proxy_pass         http://actualserver.local:3000;
            proxy_set_header   Upgrade $http_upgrade;
            proxy_set_header   Connection "Upgrade";
            proxy_set_header   X-Forwarded-Proto https;
            proxy_redirect     off;
        }

        location /.well-known/acme-challenge/ {
            root /var/www/certbot;
        }
    }
}

What I'm looking for is to get the reverse proxy to make the call to actualserver.local, instead of returning a 307. I'm a bit out of my depth here, so any help would be appreciated.

update: I tried modifying the nginx config to see if this has any effect. Here's my updated file.

worker_processes 1;

events { worker_connections 1024; }

http { client_max_body_size 0; sendfile on;

proxy_set_header   Host $host;
proxy_set_header   X-Real-IP $remote_addr;
proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header   X-Forwarded-Host $server_name;

upstream web-ui {
  server actualserver.local:3000;
}

upstream web-api {
    server actualserver.local:7066;
}

server {
    listen 80 default_server;

    server_name example.com;

    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;

    ssl_certificate     /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

    server_name     example.com;

    location /api {
        proxy_pass         http://web-api/api;
        proxy_set_header   Upgrade $http_upgrade;
        proxy_set_header   Connection "Upgrade";
        proxy_set_header   X-Forwarded-Proto https;
        proxy_redirect     off;
    }

    location /swagger {
        proxy_pass         http://web-api/swagger;
        proxy_set_header   Upgrade $http_upgrade;
        proxy_set_header   Connection "Upgrade";
        proxy_set_header   X-Forwarded-Proto https;
        proxy_redirect     off;
    }

    location / {
        proxy_pass         http://web-ui;
        proxy_set_header   Upgrade $http_upgrade;
        proxy_set_header   Connection "Upgrade";
        proxy_set_header   X-Forwarded-Proto https;
        proxy_redirect     off;
    }

    location /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }
}

}

The location being reported in the 307 is

https://web-api:7066/api/Authentication/login

The only place where web-api exists in the entire code base is in the nginx.conf, this cannot be from the application server. It has to be nginx that is doing this.