Problem with preview and revisions

Hello,

There seems to be a problem with Page Builder.
When I use the regular WP editor, new revisions are created, and preview post functions properly. When I use Page Builder the above don’t work. The posts gets saved, and the work is not lost, however, the preview doesn’t work, and there are no revisions created.

Trying to troubleshoot, I have discovered that if I publish the changes are reflected in the preview from that point on. However, upon changing the post back to draft, the preview doesn’t work anymore.

URL: http://coffee-brewing-methods.com/