DEVOPS: PROXY, REDMINE, Plesk Issue Quick Fix. -- 2

I have a strange issue

I have a REDMINE that works on the old server but after it is moved it says proxy issue and the user can not access it.

**ERROR**
[error] 9309#0: *44008 connect() failed (111: Connection refused) while connecting to upstream, client: 43.240.11.219, server: r.xxxx.com, request: "GET /favicon.ico HTTP/2.0", upstream: "http://127.0.0.1:3100/favicon.ico", host: "r.XXXXXXXX.com", referrer: "https://r.xxxx.com/"

**PROXY code in NGINX**
location / {
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header Host $http_host;
proxy_pass http://127.0.0.1:3100;
}

**Requirements:**
- PLESK
- UBUNTU 22.04
- REDMINE
- MIGRATION between servers