title: Magento 2 - Estimate Shipping and Tax cart does not calculate or include my custom shipping method's rate
body: <p>I have used a custom shipping method and when you go to the Estimate Shipping and Tax cart, my custom shipping method 'rate' is not being added into the Order Total.</p>
  
  <p>As you can see the image below. </p>
  
  <p><a href="https://i.stack.imgur.com/mtRCh.jpg" rel="nofollow noreferrer">estimate-shipping-tax-cart</a></p>
  
  <p>When I select my shipping method, the rate is shown as 0.00</p>
  
  <p>But for Flat Rate the rate is being calculated properly.</p>
  
  <p><a href="https://i.stack.imgur.com/8CT8F.jpg" rel="nofollow noreferrer">estimate-shipping-tax-cart-with-flat-rate</a></p>
  
  <p>I would like to know how to fix this and why it's happening like that.</p>