Articulate plug-in won't load after I migrated from Host Gator to WP Engine

I had WP Valet migrate my WordPress site from Host Gator to WP Engine. Everything that was moved worked well. But when I tried to add a new Articulate file after the migration using the Articulate plug-in (a), the file seemed to load, had the correct URL, but the website went to another page and the new Articulate file couldn’t be accessed at all. I couldn’t get any new Articulate files to load properly after the migration, though the plug-in worked perfectly every time before the migration.

I’d like to keep WP Engine as my host, but Articulate is the majority of my site, and I need to add new material regularly. The Articulate people say they didn’t write the plug-in and don’t support it (though it’s the only Articulate plug-in I could find for WordPress). The WP Valet people say they moved everything properly. The WP Engine people haven’t responded at all, though I created a support ticket for this yesterday, and they say customer support is a key feature of their service.

This is my first website, and I can’t open it until I figure out this issue. If you have any suggestions, please let me know. I’d like to keep WP Engine, but I have to be able to simply (hopefully, with the plug-in) load new Articulate files.

Thank you.