Twilio Conference statusCallback sends GET request instead of POST request

Question

I'm trying to create a conference on inbound voice call.

I have the following TwiML that should trigger a POST request from twilio for the following events start,end I already specifed the statusCallbackMethod to POST but twilio keeps sending GET request to the statusCallback

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Dial>
        <Conference 
startConferenceOnEnter="true" 
endConferenceOnExit="true" participantLabel="WKxxx" 
statusCallbackEvent="start,end" 
statusCallback="http://xxx" 
statusCallbackMethod="POST">CAxxx</Conference>
    </Dial>
</Response>

I already set the webhooks to POST in the Active phone numbers Webhooks

I 'am expecting a POST request in statusCallback but I keep getting GET request.