ajax - PHP Exit() won't pass message after else statement

one text

I have a PHP Script that get call using AJAX

$.ajax({
    url: "phpscript/testform.php",
    type: "POST",
    data:  {'data':formData},
    success: function(response){
        
        if(response == "OK"){
            console.log("!!");
            $("#email_sent_modal").modal('show');
        }
        if(response == "WRONG"){
            console.log("Email already exists!");
        }
        if(response == "NOTSET"){
            console.log("Info Not Set!");
        }
    }
})

Everything works fine for response =="WRONG" and response =="NOTSET"

Except for response =="OK" after MAIL for some reason. note i do not include everything above, just the important part

This is my PHP Code

if($conn){
    

            
            //SQL PREPARE STATEMENT TO INSERT INTO DATABASE
            $sql = "INSERT INTO signup (email, psw, name, lastname, company, token)
            VALUES ('$email', '$password','$name','$lastName','$company','$token') ";
            if ($conn->query($sql) === TRUE){
            $to = $email;
            $subject = "Finish signing up your ID";
            
                    $htmlContent = '<html> 
                                    <head> 
                                        <title>Password Reset</title> 
                                    </head> 
                                    <body> 
                                        <h4>Dear ' . $name . '      </h4> 
                                     <p>                
                                     Finish signing up your ID. To complete the process, click the link below. </p>
                                     <p> <a href="www.google.com'">Link </a>
                                     </body> 
                                    </html>';                                   
            $headers = "MIME-Version: 1.0" . "\r\n"; 
            $headers .= "Content-type:text/html;charset=UTF-8" . "\r\n"; 
            $mail($to, $subject, $htmlContent, $headers);
            exit("OK");
            }
        }

the SQL mailing all works, i receive email and the sql database inserted perfectly, just the exit("OK") does not send back to ajax and can't show the nothing appears on console log

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