why is the rathole connection easily broken?

[server]
bind_addr = "0.0.0.0:58000"
default_token = "xxx"
heartbeat_interval = 30

# To Loopback Address for Nginx (Public Service)
[server.services.filebrowser]
bind_addr = "10.10.11.1:58097"

[server.services.navidrome]
bind_addr = "10.10.11.1:58095"

2024-03-10T16:19:18.476494Z  INFO config_watcher{path="rathole-server.toml"}: rathole::config_watcher: Start watching the config
2024-03-10T16:19:18.476573Z  INFO rathole::server: Listening at 0.0.0.0:58000
2024-03-10T16:19:20.511616Z  INFO connection{addr=66.96.225.80:46036}: rathole::server: Try to handshake a control channel
2024-03-10T16:19:20.512472Z  INFO connection{addr=66.96.225.80:46050}: rathole::server: Try to handshake a control channel
2024-03-10T16:19:20.540801Z  INFO connection{addr=66.96.225.80:46036}: rathole::server: Control channel established service=filebrowser
2024-03-10T16:19:20.541182Z  INFO connection{addr=66.96.225.80:46036}:handle{service=filebrowser}:run_tcp_connection_pool: rathole::server: Listening at 10.10.11.1:58097
2024-03-10T16:19:20.541728Z  INFO connection{addr=66.96.225.80:46050}: rathole::server: Control channel established service=navidrome
2024-03-10T16:19:20.541900Z  INFO connection{addr=66.96.225.80:46050}:handle{service=navidrome}:run_tcp_connection_pool: rathole::server: Listening at 10.10.11.1:58095
2024-03-10T16:23:36.505543Z ERROR connection{addr=66.96.225.80:46050}:handle{service=navidrome}:run: rathole::server: Failed to write control cmds: Broken pipe (os error 32)
2024-03-10T16:23:36.505622Z  INFO connection{addr=66.96.225.80:46050}:handle{service=navidrome}:run: rathole::server: Control channel shutdown
2024-03-10T16:23:49.081750Z ERROR connection{addr=66.96.225.80:46036}:handle{service=filebrowser}:run: rathole::server: Failed to write control cmds: Broken pipe (os error 32)
2024-03-10T16:23:49.081822Z  INFO connection{addr=66.96.225.80:46036}:handle{service=filebrowser}:run: rathole::server: Control channel shutdown
2024-03-10T16:24:09.457639Z  INFO connection{addr=66.96.225.80:46050}:handle{service=navidrome}:run_tcp_connection_pool: rathole::server: TCPListener shutdown

[client]
remote_addr = "x.x.x.x:58000"
default_token = "xxx"
heartbeat_timeout = 0
retry_interval = 1

# From Loopback Address to remote_addr (Public Service)
[client.services.filebrowser]
local_addr = "127.0.0.1:8097"

[client.services.navidrome]
local_addr = "127.0.0.1:8095"

2024-03-10T16:21:47.641352Z  WARN handle{service=navidrome}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:01.977000Z  WARN handle{service=filebrowser}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:01.977151Z  WARN handle{service=filebrowser}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:08.121382Z  WARN handle{service=navidrome}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:08.121592Z  WARN handle{service=navidrome}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:08.121397Z  WARN handle{service=navidrome}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:18.361328Z  WARN handle{service=filebrowser}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:18.361314Z  WARN handle{service=filebrowser}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:20.409205Z  WARN handle{service=navidrome}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)
2024-03-10T16:22:59.320877Z  WARN handle{service=filebrowser}:run: rathole::client: Failed to run the data channel: Failed to connect to x.x.x.x:58000: Connection timed out (os error 110)