Failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED

Hello everyone,
I configured virtualhost on apache with SSL, my domain is already working normally via https: // and port 3333 is open on the server, but when trying to establish a connection with the websocket I get the following error:

failed: Error in connection establishment: net :: ERR_CONNECTION_REFUSED

It is not a problem of SSL certificate or closed port, what can it be?

Client:

const ws = Ws('wss://my-domain.net:3333')
window.ws = ws.withJwtToken(window.token).connect()