The data i get back to FETCH from my PHP file, had an added empty paragraph at the beginning

Question

I use the FETCH API to pull data from the backend, but since some time I am getting an empty paragraph at the beginning of each response. Unfortunately for me, I am not able to track down what change was made that has caused this, so I am looking for possible reasons why this would happen in order to eliminate it. Below is once such fetch:

      await fetch('__transport.php', {
        method: "POST", 
        body: new URLSearchParams("pk="+pk+"&drvr="+drvr+"&col="+col)
      })
      .then(response => response.text())
      .then((response) => {
            if(response.substr(0,6) == "Failed") {
                alert(response)
            } else {
                document.getElementById(id).innerHTML = response;
            }
       })
       .catch(err => console.log('s/g went wrong', err));

and here the backend, the mysql query was removed from the end, but it returns a name

    $pk = $_POST['pk'];
    $drvr = ($_POST['drvr'] != 0 ? $_POST['drvr']:'NULL');
    $col = $_POST['col'];
    $sql = "UPDATE mytable
          SET
            $col = $drvr
          WHERE pkcolumn = $pk";

    if ($conn->Execute($sql)==false) {
        exit("Failed to update database\n\n".$conn->ErrorMsg()."\n\n".$sql);
    } else if($drvr != 'NULL'){
        //mysql query removed for simplification as I get the same result with this
        $name = "Jack Sparrow";
        exit($name); //returns the name to the above FETCH
    } else {
        exit(' '); //returns no name as the field should be blank in this case
    }

I am expecting the return "Jack Sparrow" to be received by the JavaScript in the variable "response", as:
"Jack Sparrow"
What I get is and empty paragraph followed by the name:
"
Jack Sparrow"