Error: client closed prematurely connection

I have a problem similar to the one described here:
Re: ngx_http_do_read_client_request_body -- client closed prematurely connection - I’m seeing some
“client closed prematurely connection” errors. They seem to happen
constantly for one of our users, who is using the same software as
everyone else (browser plugin to upload files), I can’t reproduce it and
I don’t know a lot about server configuration. Can anyone help me to
find out what the problem is (or even if there is a problem)?

Nginx version 7.64 running on Ubuntu.

Posted at Nginx Forum: