Server communication error

In one type of document, after entering a large number of characters into the document’s metadata, a communication error with the server appears. When I reduce the number of characters in the metadata, everything works.

The error appears after clicking next in step 3/4

What can I change in the configuration to be able to transfer larger amounts of data?
I use nginx proxy.

Server communication error

Check you network connection and try again in a few moments.

Proxies have a default limit on the body of a request. Some proxies might raise HTTP error 413. Others don’t raise an error and just fail the connection.

For NGINX try setting:

client_max_body_size 1000M;

Unfortunately increasing client_max_body_size for nginx did not help.

server {
    listen 80 ;
    server_name ;
    location / {
        return 301 https://$host$request_uri;
server {
    listen 443 ssl http2 ;
    server_name ;
    access_log /var/log/nginx/mayan.log;
    error_log /var/log/nginx/mayan_error.log;
    client_max_body_size 1000M;  # Increase to upload bigger documents
    ssl_certificate /home/test/mayan/cert/fullchain.pem;
    ssl_certificate_key /home/test/mayan/cert/privkey.pem;
    ssl_trusted_certificate /home/test/mayan/cert/chain.pem;
    location / {
        proxy_redirect off;
        proxy_read_timeout 3600s; # Increase if your doc uploads take more than 60 sec

        proxy_http_version 1.1;
        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_pass_header Set-Cookie;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header X-Forwarded-Host   $host;
        proxy_set_header X-Forwarded-Port   443;
        proxy_set_header X-Forwarded-Proto  https;

I also increased the mayan edms options:
DATA_UPLOAD_MAX_MEMORY_SIZE: 2621440 → 26214400
FILE_UPLOAD_MAX_MEMORY_SIZE: 2621440 → 26214400
Did not help.