Magento 2 - Newsletter subscription issue - magento2

Question

I use Martfury theme. When I subscribe to newsletter, it redirects me to /newsletter/subscriber/new/ and there is this message (JSON): {"success":true,"message":"Thank you for your subscription.","redirect":false}
Image:
It should show only notification and not redirect to that URL. In Martfury theme demo it works well.
Code:

Answer 1

In your theme, please check the newsletter controller return. Debug execute function line by line.
controller path: module-newsletter/Controller/Subscriber/NewAction
Then you can check the below function:
/**
* New subscription action
*
* #return Redirect
*/
public function execute()
{
if ($this->getRequest()->isPost() && $this->getRequest()->getPost('email')) {
$email = (string)$this->getRequest()->getPost('email');
try {
$this->validateEmailFormat($email);
$this->validateGuestSubscription();
$this->validateEmailAvailable($email);
$websiteId = (int)$this->_storeManager->getStore()->getWebsiteId();
/** #var Subscriber $subscriber */
$subscriber = $this->_subscriberFactory->create()->loadBySubscriberEmail($email, $websiteId);
if ($subscriber->getId()
&& (int)$subscriber->getSubscriberStatus() === Subscriber::STATUS_SUBSCRIBED) {
throw new LocalizedException(
__('This email address is already subscribed.')
);
}
$storeId = (int)$this->_storeManager->getStore()->getId();
$currentCustomerId = $this->getCustomerId($email, $websiteId);
$subscriber = $currentCustomerId
? $this->subscriptionManager->subscribeCustomer($currentCustomerId, $storeId)
: $this->subscriptionManager->subscribe($email, $storeId);
$message = $this->getSuccessMessage((int)$subscriber->getSubscriberStatus());
$this->messageManager->addSuccessMessage($message);
} catch (LocalizedException $e) {
$this->messageManager->addComplexErrorMessage(
'localizedSubscriptionErrorMessage',
['message' => $e->getMessage()]
);
} catch (\Exception $e) {
$this->messageManager->addExceptionMessage($e, __('Something went wrong with the subscription.'));
}
}
/** #var Redirect $redirect */
$redirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT);
// phpcs:ignore Magento2.Legacy.ObsoleteResponse
$redirectUrl = $this->_redirect->getRedirectUrl();
return $redirect->setUrl($redirectUrl);
}