Hi Richard
We released new version of JA Builder long time ago which will help to store data into your site's database instead of pushing into our server.
You can backup your site & download 3 packages (package + component + plugin) here: https://www.joomlart.com/member/downloads/joomlart/ja-joomla-page-builder/ja-joomla-builder and install manually in backend of your site.
After installing, you can try editing a page via JA Builder again (don't publish it) >> just compare it with frontend of this page and see how it looks. If they look the same, you can continue to edit page and publish.
Regards