Nginx HLS Load balancer data traffic on primary server - nginx

Question

My design is:
Media Server -> edge servers (Multiple Nginx Cache server -> Nginx Load Balancer)
it is my private CDN system (for Live content delivery)
I have content source and multiple edges; in each edge, there is multiple cache server and a Load Balancer
I started step by step, so for this job I face a problem with Nginx Load Balancer.
In this configuration, I am balancing between two servers s1 and s2.
but when I check traffic by(nload), I see big traffic on the primary server(load balancer) for example from nload see s1=1GBPS s2=1GBPS loadbalancer=2GBPS
note: my content is HLS (.m3u8)
user www-data;
worker_processes 5; ## Default: 1
error_log /var/log/nginx/error.log;
pid /var/run/nginx.pid;
worker_rlimit_nofile 8192;
events {
worker_connections 4096; ## Default: 1024
}
http {
include mime.types;
include /etc/nginx/proxy.conf;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] $status '
'"$request" $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
tcp_nopush on;
# upstream
upstream origins {
server s1.ip;
server s2.ip;
}
# default route
server {
listen 80;
server_name example.com;
access_log /var/log/nginx/example.com main;
location / {
proxy_set_header Host $host;
proxy_pass http://origins;
}
}
}