Filament builder field and spatie media library

I've just started a new project using filament 3 as a CMS for a website. More specifically I'm using the builder form field type to allow the administrator to add content, images, videos, galleries etc to the page model in any order.

I'm trying to combine the builder form field with the spatie media library filament plugin but it isn't playing ball. It seems like if you have multiple image fields in your form it just attaches the same image to every one.

The media table in the database shows the image attaching to the model ok but there is nothing defining which field it belongs to. I can't see anything about it in the docs, has anyone got this plugin working correctly with the builder form field type?