GPP 1.7 beta issue with page header element

I have created a custom page header element and have assigned it to multiple custom post type categories and the related posts through the Display Rules. When I click save and try to go back to the Display Rules, the rules are not loading, there is just the spinning wheel rotating.
https://imgur.com/aHdXM17

I cleared the cache, restarted the browser and local server(Apache on Laragon), tried again, same problem. If I save while it's doing that and go back to it, the dropdown options on the right (for the selected categories) are empty. If I start again the same thing happens all over again. To reproduce, maybe ceate a couple of custom post types with the Custom Post Type UI addon, create a few taxonomies for it, add a few posts assigned taxonomies for them, create a header and try and assign it to multiple location in one of those custom post types(categories, archives, etc)