wp_set_auth_cookie() not working for some users only - php

Question

I have a login form and using REST api service for login to the Wordpress. I can login to the wordpress using the form. But for some users wp_set_auth_cookie() function not working and I am getting 502 bad gateway. Can any one help me for sort out this?
This is my login endpoint function
function user_authentication() {
global $wp_rest_auth_cookie;
if(strcasecmp($_SERVER['REQUEST_METHOD'], 'POST') != 0){
throw new Exception('Request method must be POST!');
}
$contentType = isset($_SERVER["CONTENT_TYPE"]) ? trim($_SERVER["CONTENT_TYPE"]) : '';
if(strcasecmp($contentType, 'application/json') != 0){
throw new Exception('Content type must be: application/json');
}
$content = trim(file_get_contents("php://input"));
$decoded = json_decode($content, true);
if(!is_array($decoded)){
throw new Exception('Received content contained invalid JSON!');
}
$user_data['user_login'] = $decoded['username'];
$user_data['user_password'] = $decoded['password'];
$user_data['remember'] = false;
$user = wp_signon( $user_data, false );
if ( !is_wp_error( $user ) ) {
wp_clear_auth_cookie();
wp_set_current_user ( $user->ID);
wp_set_auth_cookie ( $user->ID );
$wp_rest_auth_cookie = wp_create_nonce('wp-rest') ;
$token = encrypt_decrypt('encrypt',$user->ID);
$name = get_name($user->ID);
$response = array(
'status'=> 'success',
'token' => $token,
'username' => $name,
'uname' => $user->ID
);
return json_encode( $response);
}else{
$response = array(
'status' => 'fail',
'message'=> "The username and password you entered don't match."
);
return json_encode($response);
}
die();
}

Answer 1

Add below code into your code and check wp_set_auth_cookie working or not.
$user_data['user_login'] = $decoded['username'];
$user_data['user_password'] = $decoded['password'];
$user_data['remember'] = true;
$user = wp_signon( $user_data, false );
if ( !is_wp_error( $user ) ) {
wp_set_auth_cookie( $user->ID, true );
} else {
echo $user->get_error_message();
}

Answer 2

I have solved this myself. There was some undefined variable errors along with the api response. Those errors was conflicting with the wp_set_auth_cookie() function. When I fixed those errors from my code, the 502 bad gate way issue get solved.