title: PayPal Instant Update for Express Checkout stopped working [sandbox]
body: <p>I spent like four weeks coding a plugin to work with PayPal Express Checkout instant update. It was working perfectly in the end with shipping and taxes updating as expected.</p>
  
  <p>However, two days ago, the checkout layout got changed automatically from the classic one to the mobile-responsive version. Previously when I had the callback for instant update defined it automatically used to switch from the mobile-friendly version to the classic version. Now that is no longer the case and the instant update features don't seem to work at all with the mobile-friendly checkout.</p>
  
  <p>Is there anything I can do about it or has PayPal stopped supporting instant update just when I finished my plugin?</p>