APP_URL Behaviour

[NerdBlender]

I have my snipe-it on a subdomain of the server, all was fine until i updated snipe-it, and it seems the app_url doesnt seem to work correctly. I can basically set it to anything, clear the cache and it ignores it, i'm not sure if its nginx causing some issues, but my nginx config looks like this:

`server {
listen 80;
server_name localhost server server.domain.com;
rewrite_log on;
error_log /var/log/nginx/localhost.error_log notice;

root /opt/docuwiki;
index index.php index.html index.htm;

location /assets {
    alias /opt/snipe-it/public;
    try_files $uri $uri/ @assets;

    location ~ \.php$ {
       fastcgi_pass unix:/run/php/php7.4-fpm.sock;
       fastcgi_index index.php;
       fastcgi_param SCRIPT_FILENAME $request_filename;
       include fastcgi_params;
    }
}
location @assets {
 # rewrite /assets/(.*)$ /assets/index.php?$args last;
  rewrite ^(.+)$ /assets/index.php/$1 last;
}

location ~* /(data|conf|bin|inc|vendor)/ {
  deny all;
}
location / {
    try_files $uri $uri/ /index.php$is_args$args;
}

location ~ \.php$ {
    try_files $uri $uri/ =404;
    fastcgi_pass unix:/run/php/php7.4-fpm.sock;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
}

}
`

My snipe-it APP_URL is set to http://server.domain.com/assets

With this config, all my links are broken. if i make a simple nginx file that has the snipe-it as the document root, I can basically set the APP_URL to any subdomain - i currently have it set to server.domain.com/cabbage and it has no affect, but changing the server name to cabbage.cabbage.com does.

I'm not sure why running the snipe-it upgrade broke it