managed to solve the problem? I have the same situation Odoo 16 Nginx

# Odoo servers
upstream odoo {
server 127.0.0.0:8069;
}
upstream odoochat {
server 127.0.0.0:8072;
}

# HTTP -> HTTPS
server {
listen 80;
server_name  www.portal.eximlab.ua portal.eximlab.ua;

location ^~ /.well-known/acme-challenge/{
allow all;
root /var/lib/letsencrypt/;
default_type "text/plain";
try_files $uri =404;
}

return 301 https://portal.eximlab.ua$request_uri;
}

# WWW -> NON WWW
server {
listen 443 ssl http2;
server_name www.portal.eximlab.ua;

ssl_certificate /etc/letsencrypt/live/portal.eximlab.ua/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/portal.eximlab.ua/privkey.pem;
ssl_trusted_certificate /etc/letsencrypt/live/portal.eximlab.ua/chain.pem;

return 301 https://portal.eximlab.ua$request_uri;
}

server {
listen 443 ssl http2;
server_name portal.eximlab.ua;

proxy_read_timeout 720s;
proxy_connect_timeout 720s;
proxy_send_timeout 720s;

# Proxy headers
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Real-IP $remote_addr;

# SSL parameters
ssl_certificate /etc/letsencrypt/live/portal.eximlab.ua/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/portal.eximlab.ua/privkey.pem;
ssl_trusted_certificate /etc/letsencrypt/live/portal.eximlab.ua/chain.pem;

# log files
access_log /var/log/nginx/odoo.access.log;
error_log /var/log/nginx/odoo.error.log;

# Handle longpoll requests
location /longpolling {
proxy_pass http:// 127.0.0.0:8072;
}

# Handle /requests
location /{
proxy_redirect off;
proxy_pass http://odoo;
}

# Cache static files
location ~* /web/static/{
proxy_cache_valid 200 90m;
proxy_buffering on;
expires 864000;
proxy_pass http://odoo;
}

location ^~ /.well-known/acme-challenge/{
allow all;
root /var/lib/letsencrypt/;
default_type "text/plain";
try_files $uri =404;
}

# Gzip
gzip_types text/css text/less text/plain text/xml application/xml application/json application/javascript;
gzip on;
}

At first i would change the network adress (127.0.0.0) to the host adress in the network (127.0.0.1). Futhermore i would use the upstrem server odoochat in longpolling location instead of IP again.

Check and tell about your findings