I just upgraded your core plugin from 4.11.1 to 4.12.2 and now there is a bug which prevents reordering photos using your image advanced field in FireFox. When I attempt to reorder my images it opens up WP's Upload to Media Library window. I have tested this on two different websites that I'm using your plugin for and the bug happens on both sites when I upgrade to 4.12.2.
This doesn't happen in Chrome, however both Chrome and FireFox throws javascript errors in the browser console.
FireFox console throws the following JavaScript error: