This includes all synchronous AJAX requests that are executed on page unload (when navigating away from a page or when closing the browser/tab).
XHR requests on page unload are often used by SCORM & xAPI packages to send learners’ progress, so this change can possibly affect users viewing SCORM/xAPI units with the Chrome browser.
What can you do?
As a short-term workaround, a user can disable this behaviour by typing “chrome://flags” in Chrome’s address bar, searching for “Allows synchronous XHR requests in page dismissal” setting, and setting its value to “Disabled”. This option will be removed after Chrome version 85, Oct 21, 2020.
We recommend you check all your SCORM/xAPI packages, and update them accordingly, so that they do not use any synchronous XHR calls during page dismissal.