The specific situation is:
I have an app (rails passenger nginx), which provides an upload function for users to upload files.
I deployed it to the server and tested it

1: It’s OK to upload files using my computer

2: It’s OK to upload files using the computer in my company

3: When providing it to collaborators, the page link is interrupted when the file is uploaded halfway.

4: The collaborator used his company’s computer to upload, but the link was interrupted halfway through the upload.

5: Collaborators can sometimes upload (the probability is very small) most of the time the page is broken after uploading half way

I logged in to the server and checked the logs and found that nothing abnormal happened.

ps: The collaborator has redone the system before (it was able to upload before the system was built). He used the Firefox browser and IE browser, but failed
I guess there is a problem with the collaborator's network. There is also a possibility that there is a problem with my nginx configuration.
At present, I have not found a suitable entry point to investigate this problem. I will post the problem first and hope that everyone can help with ideas

The following is my nginx configuration file:

include       mime.types;
default_type  application/octet-stream;
log_format  simple '$remote_addr - [$time_local] "$request" $status $body_bytes_sent';
log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';

#access_log  logs/access.log  main;

sendfile        on;
#tcp_nopush     on;

#keepalive_timeout  0;
keepalive_timeout  180;


include /opt/nginx/conf/sites-enabled/*;