First of all, really excited about the ability to use cloneable fields. Awesome feature.
Here's my process I have custom fields assigned to post. They include a cloneable group consisting of two fields, one a Post type field, (ie. Select item from a another cpt) and the other a text field.
I've created a Metabox Group/Skin in the Elementor Theme builder.
When I insert the Meta Box Group widget and select my group, it displays the straight Text data properly, showing the ID from the post type field and the text form the text field.
When I select the Skin drop down, my only option is Select a Skin. I've created multiple Skins, but none are loading in the drop down and if I search their names, nothing shows up. If I click the Edit/Create Skin button, I'm brought to the page showing all my created skins. Is there some setting I need to adjust to have them visible/selectable?