Cannot connect Flask-SocketIO with unity

Question

I need to connect unity(.net) with flask_socketIo, In short, the connection works well between the server and the client locally, but never online.

I used a unity wrapper for this link very simple to use:

 public void testIO()
 {
     KyleDulce.SocketIo.Socket s;
     s = SocketIo.establishSocketConnection("ws://localhost:5000"); 
     s.connect();
     s.on("OCR", OnConnectRespond);
 }
 public void OnConnectRespond(string m){ Debug.Log("msg: " + m); 

and the flask application looks like this

from flask import Flask
from flask_socketio import SocketIO, emit
async_mode = None
#eventlet
import eventlet
import eventlet.wsgi
eventlet.monkey_patch()

app = Flask(__name__)
app.config['SECRET_KEY'] = '<hiddenValue>'
socketio = SocketIO(app, async_mode='eventlet')


@socketio.event()
def connect():
    print(f'you are CONNECTED!')
     emit('OCR',"a Msg from the server")

if __name__ == '__main__':
    socketio.run(app,debug=True,port=5000)

that works locally without any issues, as soon as I fire testIO() the server receives the connection and OCR() gets fired without any issues.

but as soon as I tried to deploy that on Cpanel python app the server never received any connection attempts. of course I have changed the server from localhost to the actual domain name, here is what I have tried so far on the client side :

s = SocketIo.establishSocketConnection("ws://example.com:5000");

s = SocketIo.establishSocketConnection("https://example.com:5000");

s = SocketIo.establishSocketConnection("http://example.com:5000");

s = SocketIo.establishSocketConnection("ws://example.com");

s = SocketIo.establishSocketConnection("https://example.com");

none of them worked.

I read somewhere that socketIo server host parameter default is localhost so I've tried to change that to the website domain.

s = SocketIo.establishSocketConnection("http://example.com");

if __name__ == '__main__':
    socketio.run(app,host='https://example.com',debug=True,port=5000)

unfortunately, it didn't work either.

there's nothing useful on the server console (online or locally), it just doesn't connect when something goes wrong.

I got a gut feeling that could be due to some certification/headers, but I can't be sure and I don't know how to add those to SocketIO, I can make WWW request from unity just fine and I get the server response everytime.

Update:

Logs on cpanel are slow for some reason ( it takes from minutes - hours ), I've logged today and I have noticed too many of this error are pileing up

[ERROR] [UID:9279][1527766] wsgiAppHandler pApp->start_response() 

return NULL.
[ERROR] [UID:9279][1527766] wsgiAppHandler pApp->start_response() 
return NULL.

UPDATE:

I ended up making my own Logging system, here is what I found.

2022-04-12 13:50:02,570:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/flask/app.py", line 2091, in call 2022-04-12 13:50:02,572:WARNING:foobar:return self.wsgi_app(environ, start_response) 2022-04-12 13:50:02,572:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/flask_socketio/init.py", line 43, in call 2022-04-12 13:50:02,572:WARNING:foobar:return super(_SocketIOMiddleware, self).call(environ, 2022-04-12 13:50:02,572:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/engineio/middleware.py", line 63, in call 2022-04-12 13:50:02,573:WARNING:foobar:return self.engineio_app.handle_request(environ, start_response) 2022-04-12 13:50:02,573:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/socketio/server.py", line 597, in handle_request 2022-04-12 13:50:02,574:WARNING:foobar:return self.eio.handle_request(environ, start_response) 2022-04-12 13:50:02,574:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/engineio/server.py", line 398, in handle_request 2022-04-12 13:50:02,575:WARNING:foobar:r = self._handle_connect(environ, start_response, 2022-04-12 13:50:02,575:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/engineio/server.py", line 573, in _handle_connect 2022-04-12 13:50:02,576:WARNING:foobar:ret = s.handle_get_request(environ, start_response) 2022-04-12 13:50:02,576:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/engineio/socket.py", line 103, in handle_get_request

2022-04-12 13:50:02,576:WARNING:foobar:return getattr(self, 'upgrade' + transport)(environ, 2022-04-12 13:50:02,576:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/engineio/socket.py", line 158, in _upgrade_websocket

2022-04-12 13:50:02,577:WARNING:foobar:return ws(environ, start_response) 2022-04-12 13:50:02,577:WARNING:foobar: File "/home//virtualenv/ppy/3.8/lib/python3.8/site-packages/engineio/async_drivers/eventlet.py", line 16, in call

2022-04-12 13:50:02,578:WARNING:foobar:raise RuntimeError('You need to use the eventlet server. ' 2022-04-12 13:50:02,578:WARNING:foobar:RuntimeError 2022-04-12 13:50:02,578:WARNING:foobar:You need to use the eventlet server. See the Deployment section of the documentation for more information. 2022-04-12 13:50:02,578:WARNING:foobar:<wsgi.LoggerWriter object at 0x2b77bd4eb3a0>

it seems to me that eventlet is not implemented correctly for some reason, I found online that socketIO.run() would look for eventLet or gevent and if any exists, it would use them instead, but that is not what is happening here appearntly.