php 8.1 html email in raw formaat

class CHmail{
    var $to = null;
    var $from = null;
	var $reply = null;
    var $subject = null;
    var $body = null;
    var $headers = null;

   public function __construct($to,$from,$reply,$subject,$body){
        $this->to      = $to;
        $this->from    = $from;
		$this->reply    = $reply;
        $this->subject = $subject;
        $this->body    = $body;
    }



     public  function send(){
		 
      $this->addHeader('From: '.$this->from." <".$this->reply."> \n");
        $this->addHeader('Reply-To: '.$this->reply."\n");
        $this->addHeader('Return-Path: '.$this->from."\n");
        $this->addHeader('X-mailer: ZFmail 1.0'."\n");
		$this->addHeader('Content-type: text/html; charset=utf-8'."\n");
    

	
	    mail($this->to,$this->subject,$this->body,$this->headers);
    }

    function addHeader($header){
        $this->headers .= $header;
    }

}

Dan gebruik ik de mail zo

ob_start();
						include(DOC_ROOT.'inc/email_contact.php');
						$myHTML = ob_get_clean();
						$bericht = preg_replace('~[\n\r\s]+~',' ', $myHTML);						 
						$email = 'info@'.TRADE_URL.'';
						$mailReg = new CHmail($_POST['contact-email'],$from,$reply,'Contact '.TRADE_URL.'',$bericht);
						$mailReg->send();	

De mail word verstuurd in Raw format.
Terwijl dit html emails zijn.
Dit is gebeurd net toen ik de overzetting naar php8.1 heb gemaakt;
In php 7.3 werkte alles prima.

Kent iemand dit probleem?