Dashboard didn't showed any data on VPS

So i tried to connected my device on VPS with DHT Sensor, in Devices -> API Explorer there is data received, but when i try to create a dashboard, there are no data to show up and when i check my browser console i noticed something said

WebSocket connection to ‘ws://mydomain/v2/users/user/devices/device1?authorization=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE1NjIzMDIyMTUsImlhdCI6MTU2MjI5NTAxNSwidXNyIjoid2lhbm9za2kifQ.B-9GBb0E9QBD0hUwfQqtYEV-gHaHx67zdFkKz73BiXM’ failed: Error during WebSocket handshake: Unexpected response code: 200

how can i fix this issue ? thank you very much