\Drupal::messenger()->addMessage Logs out user automatically

Question

I'm working on a Drupal 10 offsite payment module. I'm trying to show Drupal message whenever order gets placed, declined, or failed. Please see code snippet:

module file: Drupal\my_module\Plugin\Commerce\PaymentGateway\LatpayRedirect.php

  public function onReturn(OrderInterface $order, Request $request) {
  //\Drupal::logger('commerce_payment')->notice('onReturn function called.'); 

    $amount = $request->get('amount');
    $status_code = $request->get('Status');
    $merchant_ref_number = $request->get('merchant_ref_number');
    $currencydesc = $request->get('currencydesc');
    $transaction_id = $request->get('Transactionid');
    $Requestid = $request->get('Requestid');
    $CardLast4 = $request->get('CardLast4');
    $CardType = $request->get('CardType');

    // Concatenate the merchant_ref_number and the last 4 digits
    $remote_id = $merchant_ref_number . '.' . $CardType . ' Card ending in ' . $CardLast4;

    // Create and save payment entity.
    $payment_storage = $this->entityTypeManager->getStorage('commerce_payment');
    $payment = $payment_storage->create([
        'state' => 'completed',
        'amount' => $order->getBalance(),
        'payment_gateway' => $this->parentEntity->id(),
        'order_id' => $order->id(),
        'remote_id' => $remote_id,
        'remote_state' => $status_code,
    ]);

    $payment->save(); 

    // Check the status code returned from the payment gateway.
    if ($status_code == '00') {
      // Payment was successful.
        \Drupal::messenger()->addMessage($this->t('Your payment was successful. Status Code - @status / Reference number - @merchant_ref_number / Transaction ID - @transaction_id.', ['@merchant_ref_number' => $merchant_ref_number, '@transaction_id' => $transaction_id, '@status' => $status_code]), 'status');  

    }
    elseif ($status_code == '05') {    
    // Transaction Failed / Declined.
 
        \Drupal::messenger()->addMessage($this->t('Payment declined. Please try again with correct card details. Status Code - @status / Reference number - @merchant_ref_number / Transaction ID - @transaction_id.', ['@status' => $status_code, '@transaction_id' => $transaction_id, '@merchant_ref_number' => $merchant_ref_number]), 'error');  

      $order->set('state', 'pending');
      $order->save();
 
    }
  }


  public function onCancel(OrderInterface $order, Request $request) {
    $status_code = $request->get('Status');
    //$merchant_ref_number = $request->get('Merchant_ref_number');

     \Drupal::messenger()->addMessage($this->t('Status Code : @status / You cancelled before making payment but you may resume the checkout process here whenever you are ready.', [
          '@status' => $status_code,
          //'@merchant_ref_number' => $merchant_ref_number,
        ]), 'error');
  } 

The problem is - it logs out user everytime the order is placed or transaction failed. While performing a test, I commented out those drupal messenger, and it started working fine. It didn't logged me out then. So I knew who the culprit was.

I have been stuck for days. Can someone please help me why this happening and what I could do to resolve or any alternate solution? Thanks a lot.

Update: Here's the thing, for me it's very urgent and I genuinely need help to resolve this issue asap no matter if I have to pay few bucks. So Whoever helps me will get paid with bounty. Please guys!! Help.