Too many websocket connection between Tyk / Server

Hi
I have some strange connections with WebSocket between tyk api and server.
The client exits and closes their connection, but Tyk API gateway has still connection from the server. And Client - Tyk API gateway is normal.
So, I tried to close tyk/server connection with “proxy_close_connections”. But it doesn’t work on WebSocket connection.
Please help me with this issue.

My tyk.conf is belows:
“close_connections”: true,
“proxy_close_connections”: true,
“http_server_options”: {
“enable_websockets”: true
},
“close_idle_connections”: false,
“global_session_lifetime”: 100,
“force_global_session_lifetime”: false,
“max_idle_connections_per_host”: 100