does nginx (1.20 or newer) re-resolve DNS for proxy_pass?

I can confirm that resolver not working when i did the same setup like above

resolver 10.0.0.2 valid=10s;

server {
    location / {
        set $backend_servers backends.example.com;
        proxy_pass http://$backend_servers:8080;
    }
}

nginx v1.24.0 and v.1.25.2, both of them do not work. Seems like they going to take care nginx plus version too much and forget to fix this in the open source version.