I'm having the same problem, except it's with Image Advanced, with multiple images saved to the post. Not only does it only return an ID instead of an array of stuff, it only returns ONE ID, even if there's more than one pic saved to that post.
I've turned off all non-MB plugins, switched the theme to Twenty Twenty, and it's still happening.
I confirmed in the database that all three images exist for that post in wp_post_meta.
Since I turned off my plugin that defined the CPT that has the Image Advanced, the way I declared the field doesn't matter (it wasn't in a group, though).
Here is what I put in a template file - putting in the post ID of the CPT post that has the images, since that CPT doesn't exist right now, but it still returns a single integer, matching one of the 'meta_value' fields of the images I put on the post.
var_dump(rwmb_meta('product_gallery', array('size' => 'full'), '345'));
This gives me
string(3) "525"
output on the page.
Thank you for any help you can provide!
