coroutine was expected error. Service to call http to local webserver to control LG tv prior 2012

[amoranvalero]

Hello I am trying to send the power off command to an LG TV prior to 2012 vis http post query.

The code is trigger as a service power_off_async and executed properly (using a tasked coroutine) but I always have an error entry of type TypeError: a coroutine was expected, got None in line 31 at the end of async getSessionid coroutine.

The script:

import sys
import xml.etree.ElementTree as etree
import aiohttp
import asyncio
import platform


headers = {"Content-Type": "application/atom+xml"}
pairCmd = "<?xml version=\"1.0\" encoding=\"utf-8\"?><auth><type>AuthReq</type><value>" \
          + "DDHXTF" + "</value></auth>"


async def getSessionid(csa):
    async with aiohttp.ClientSession() as session:
        response = await session.post(url="http://192.168.1.143:8080/hdcp/api/auth",
                                      data=pairCmd,
                                      headers=headers)
        readout = response.text()
        tree = etree.XML(readout)
        sessionId = tree.find('session').text
        

        cmdText = "<?xml version=\"1.0\" encoding=\"utf-8\"?><command><session>" + str(sessionId) \
              + "</session><type>HandleKeyInput</type><value>" \
              + str(csa) \
              + "</value></command>"
        await session.post(url="http://192.168.1.143:8080/hdcp/api/dtv_wifirc",
                                      data=cmdText,
                                      headers=headers)
                                      
                                      
@service
def power_off_async():
    
    loop = asyncio.get_running_loop()
    task = loop.create_task(getSessionid(8))
    await task

I don't understand since the service power_off_async is called and the tv turn off but there is always an error flagged in the error log of HA.